Process to Craft Flawless Life Cast


Body casting is a popular type of art in which the human form is replicated in three-dimensional constructions. Full body castings are frequently created by experienced casting artists for theatrical or other aesthetic purposes, such as movie props. These castings are often made with skin-friendly and environmentally friendly mold making materials. Two typical materials used to create the master copy of the subject are alginate and plaster.

Generally, any life casting is completed in three pieces - head, rear and the torso. After separately making each of these parts, they are then seamed with each other through careful and precise techniques. The head is generally the last part to be attached to the cast.

Once removed from the mold, the body casts typically needs elaborate finishing touches.

To give it a semi-gloss, sometimes artists add polyurethane varnish for a pleasant look. Some life casting material kits comes with a specialized form of wax which when polished on the cast gives a marble-like shine. Depending on the need of the casts, the final color or the look can be done.



Playing with Temperatures for Better Resin Casts

The temperature of the resin as well as the room should be on the warmer side to ensure that the resin castings cure properly and are free of bubbles. Following are some tips on how to get the temperature right.

Resins come as a two part system – the resin and hardener (or catalyst) have to be mixed together in the specified ratio to make it workable. Here, it is not only about how the two parts are mixed, but also the temperature at which they are used.

Indeed, the temperature of the resin mix as well as the room will determine the quality of the resin casting!

Manipulating the temperature

Resin cures best in warm and dry environments. In case the resin is too cold, it will become thick and may not mix properly. Moreover, the mixing procedure will tend to trap air which will show up as pesky air bubbles in the cast. The resin also fails to cure properly in a cool room and will turn out soft, bendy or with cloudy streaks.

On the other hand, when the resin, hardener and the surroundings are warm enough, they will support the chemical reaction that is essential for the curing to take place.

So, if the resin and hardener are not warm enough, they need to be heated prior to use. The trick here is to place the bottles in warm water for around 10 minutes before mixing. Do not use too hot or boiling water as it will accelerate the curing, thus shortening the pot time. The resin may start curing even before it has been cast!

Another point to note is that the bottles should be dried properly after removing from the water as any droplets of water that fall into the mix can again affect the curing.

In a similar vein, the temperature of the art studio should be maintained around 70℉ to 75℉. If the space is cooler, it is advisable to turn up the heat in the room and close the door prior to starting the casting process. This will even dry up the room a bit. However, ensure that the temperature stays stable as any drop in the mercury can again delay the curing time of the resin.

Some artists even go as far as warming up the mold with a heat tool to ensure a perfect casting! Another option is to use a ‘hot box’ to keep the air around the curing resin warmer than the temperature of the room. Then again, do not overdo the heat either as the resin will cure too quickly in hot surroundings.

EnvironMolds is a one-stop shop for everything to do with mold making, casting and life casting. It offers top quality materials, supplies and tools including all types of resins and polyurethanes for making exquisite casts. The range covers jewelry resins, clear casting resins and even a special formula that can increase the size of the casting by 160%.

Standard Procedures for Making a Silicone Mold

With silicone being a popular and useful mold making material that delivers variety of benefits, artists should be aware of the basics when working with this rubber. Following are some tips on the same.

There are varied options of materials when it comes to making molds. While any malleable material like clay, wax, alginate or resin can be used to create a negative of the master model, rubbers have emerged as the material of choice, especially for professional mold makers. Then again, while there is a choice of polyurethane, latex and thermoset mold rubbers, silicone is preferred for many a reason.

To start with, mold making silicone is easy to use. The material has sufficient working time and cures fairly quickly to deliver durable, tear resistant and heat resistant molds. In fact, the molds will last for years and can be used to make any number of castings.The molds do not shrink much either. A variety of materials – like wax, plaster, gypsum, resins and even low-temperature melt metal alloys – can be cast in a silicone mold. Demolding is also easy as silicone does not stick to anything except itself.

Basic Preparation

Silicone rubber can be used to make molds of anything from figurines, statues, architectural pieces and picture frames to soaps, candles, toys, jewelry and more. The applications also include conventional prototype tooling and stereolithography.

The silicone has to be mixed with the catalyst in the specified ratio prior to use. Both the base and catalyst should first be stirred in their own containers before weighing the required amount of silicone base into a clean mixing container. A useful tip is to tilt the container and roll the material all the way around the sidewall, leaving about two inches from the top. This may sound unnecessary at first, but the coating will work to keep the catalyst from getting absorbed into the container, thus giving a better mix.

After this, the required amount of catalyst can be weighed into the container. Mix the two together by stirring with a stiff, flat-ended metal spatula until a uniform color is obtained. It is better to keep scraping the container walls and bottom to insure a thorough mix.

While artists usually vacuum degas the silicone rubber mix, it is generally not needed for most applications as a uniform flow into the mold box is enough to minimize entrapping of air. In case it is being deaired, the mixing container should be filled only to one-third of its depth to allow sufficient room for expansion during the deaeration.

Additionally, it is noted that low temperature and humidity increases both the work and pot life of silicone rubbers. Some artists even opt to refrigerate the base material before using it in hot environments.

Finally, the catalyst container should be closed tightly after use as exposure to air for an extended period can cause a film or crust to form on the catalyst and this hydrolyzed material will lead to improper curing.

MoldRite 25 Silicone is a popular material for general silicone mold making. The quality of impressions captured by these silicone molds is exceptionally outstanding.

Effect of Temperature on Mold Making and Casting

Temperature can play havoc with the curing of molds and casts by delaying/accelerating the process or not allowing the material to cure at all. Knowledge of the properties will ensure better results.

It is not just about the technique or dexterity of the artist; the quality of the mold or cast is affected by many other characteristics as well. Temperature plays a starring role here – ranging from the temperature and humidity of the surroundings to even the warmth/coldness of the material and model/mold.

This is why it is always recommended that all rubber and resin compounds should be stored at room temperature (72°F/23°C). For instance, if a material is stored at elevated temperatures, like in a hot garage or in direct sunlight, both the shelf life and pot time will get reduced drastically. In contrast, if latex rubber freezes, it becomes unusable and has to be thrown away. Other frozen materials can still be used after they are brought back to room temperature.
Let us take a look at how the temperature factors can affect the making of molds and casts:

Cold – A cold environment will usually prolong both the working time and cure time of most materials like epoxy resins, urethane rubbers and platinum cure silicones. The evaporation process of latex rubber also gets delayed in colder temperatures. In case the environment is too cold, some of these materials may even fail to cure at all. However, tin-cured silicones are not as dramatically affected by colder temperatures.

Heat – The opposite is also true as higher temperatures are known to accelerate the cure time and most materials tend to cure much more quickly when it is hot. In fact, many artists deliberately apply heat to hasten the curing process. However, tin-cured silicone rubbers are again an exception as they are not as affected by heat and cannot be ‘heat cured’.

Humidity – Rubbers are best used in a low humidity environment. Higher humidity tends to accelerate the curing in tin-cured silicone rubbers while it has the opposite effect of slowing the evaporation and curing process in latex rubbers. Making molds or casts of urethane rubbers, plastics or foams in humid environments can cause bubbles or foaming in the material. However, platinum-cured silicones and epoxy materials are not affected by humidity.

In addition to this, if the model that is being used to make the mold happens to be too cold, the curing of the mold will take unnecessarily longer to cure and vice versa. Therefore, the model/mold should be brought to room temperature prior to use. When making a mold of a frozen model, it will start condensing once the mold material is applied which will in turn delay the curing. This is why it is better to use accelerated silicones as they will not be affected by the moisture.

Finally, good quality liquid latex rubber, silicone or epoxy materials can be easily sourced from EnvironMolds at at the most reasonable prices.

Making Body Molds with Plaster Bandages

Who says plaster bandages can only be used to make a mother mold? The plaster infused gauze can also be applied directly on some parts of the body to make form molds that are later used for life casting.

Plaster bandages are normally used to make a shell mold to reinforce the flexible alginate or silicone body molds. The plaster in the bandages sets to form a rigid structure that encases the flexible mold and helps it retain its shape.

However, the plaster bandages can directly be applied on the skin to make form molds as well. This is used on areas like the stomach, back, thighs and arms which do not have much contours or undercuts. The bandages are most common for making pregnancy molds of the abdomen to capture the shape of an expecting mother for posterity.

Following is a look at what goes into making a body mold with plaster bandages:

  • The model has to be prepped for the session – the artist should inform him or her about the process, like what to expect and how much time it will take. Discuss the pose and ensure that the model can stay in the position for half an hour or so. Props or support may be required.
  • Prepare the area for the session by lining the floor with a waterproof covering as the dried plaster can prove difficult to remove. The artist should also wear a protective apron or old clothing that can be discarded later.
  • An appropriate mold release – like petroleum jelly or olive oil – should be applied on the body as this will make it easy to remove the mold without pulling on the body hair.
  • The bandages have to be rolled out and wet before applying. Here it is better to use warm water as the wet bandage can chill the skin and become uncomfortable for the model.
  • Lay the strips on the body one at a time starting from the top and moving towards the bottom. Make sure to overlap them to form a strong mold. It is better to keep changing the direction of the bandages when building the layers and make them thicker at the edges. This will serve as a good grip when it comes to demolding.
  • Work out the air bubbles when applying the bandages. However, do not press down too hard as this will form dents and can even deform the mold.
  • Once done, let the mold set and dry before demolding. Carefully run a finger under the edges to break the seal from the skin. The mold can then be lifted off easily from the body.
  • Place it on a soft surface with the hollow side down and let it cure properly. It can then be varnished for some extra protection.

Plaster gauze bandages and other materials and supplies needed for making a life cast can be easily sourced at EnvironMolds. The art supplier manufactures and stocks top quality products and tools and is more than willing to assist with tips and instructions as well.


How to Paint on Silicone Rubber?

Silicone molds and casts always throw up the problem of proper finishing as regular paints cannot be used on this rubber surface. Specially-formulated silicone paints are the best solution.

Silicone rubber proves to be a wonderful material for making both molds and casts. It is easy to use, captures details well and cures quickly too. The best part is that as silicone does not stick to anything, it is easy to demold as well, even without using a release agent.

However, this very property becomes self-defeating when it comes to painting a silicone surface. Regular oil and acrylic paints fail to adhere properly to silicone molds and casts; they will start peeling and cracking soon. This proves to be very frustrating for artists; some even resort to roughing the silicone surface so that the paint can stick on it.

Bringing an answer to the fore

There is silicone paint that has been specially formulated to work on silicone surfaces. Available in a dye form, it should be mixed with a suitable silicone paint medium – just like oil paints are mixed with linseed oil for thinning. This medium is actually a silicone catalyst which works to transform the paint so that it can permanently bond with the silicone surface that has to be painted. As the paint is also flexible, it will easily stretch and bend along with the rubber without causing any cracks or breaks. In fact, the paint can even work to protect and preserve the surface from regular wear and tear.

Silicone paint is usually used extrinsically to paint the silicone surface after it has set. The dried surface is cleaned with acetone before painting by hand. Alternatively, the color can be airbrushed on silicone (do clean the airbrush immediately to prevent clogging). For intrinsic coloring, a few drops of the pigment can be added to the silicone base before adding the catalyst.

However, bear in mind that silicone pigments can be added to tin-based silicone rubbers only. If mixed with silicone that has a platinum catalyst, it can interfere with the setting of the rubber.

EnvironMolds offers top quality silicone pigments in a broad range of color options – from black and white to red, blue, yellow, green, orange, purple and more. There is also the 'Quinn Blush' shade which is used by renown doll rebirthing artist, Terry Quinn to add the lovely skin blush to her silicone dolls.

The best part is that this silicone paint can be used on both tin-based and platinum-based silicone rubber surfaces as they have been formulated to adhere to both types of surfaces. Medium for making the paint is also available.

Therefore, artists can easily paint their silicone casts in the desired colors to get the effect they wish. They are especially favored by special effects and prosthetic artisans, doll makers, etc. to give the painted-on color effects to their silicone rubber creations. However, they can be used on regular silicone molds and casts too.

Tips for Working with Plaster for Making Castings

Fine art casting plaster is the material of choice for making casts. This is high-definition and yet easy to use as long as the proper mixing and pouring directions are followed. Find some more tricks here.

Plaster is considered the most common medium for making casts. It creates a rigid form with a lovely white finish that will stand the test of time. Plaster casting is often favored by artists over and above silicone or polyurethane rubber, and for good reason at that. In fact, it is the material of choice for making life castings as well.

However, the plaster used for castings is not the regular plaster of Paris as it tends to get chalky and flaky and will not be able to hold details well. Special plaster powders are available that have distinct additives and have been heat treated which alters these natural properties of plaster. In this way, it becomes suitable for fine art casting as the plaster cast can hold details without chipping or cracking.

This material is quite easy to use. Just mix the plaster powder in the specified quantity of water and it will be ready to use. Keep in mind that the water should be at room temperature and it is better to add the plaster powder to the water and not vice versa. The mixing can be done by hand (with gloves) or an electric mixer while taking care to avoid air from entering the mix as it can lead to air bubbles in the cast.

The plaster mixture is quite workable. One of the secret tricks is to apply a thin coating all over the surface of the mold and allow it to set a little. Then pour the mixed plaster slowly and in a thin stream to avoid air pockets.

It will set and cure naturally to a fairly hard structure. In fact, the cast should be demolded when it has set hard, but still feels a little on the wet side. There is no need to worry as the plaster can still be carved or tooled even after it has cured. Just sprinkle some water to wet the surface and it will be ready to use.

Another tip is that working with plaster can get quite messy. Therefore, artists prefer to clean as they go to keep the dust and waste from piling up. Also, keep in mind that plaster should never be applied directly on the body as the material releases heat as it cures which can cause burns at times. However, plaster bandages are sometimes used to make form body molds.

Best option

CastRite Art Casting Stone is a fine plaster powder that gives a natural, bright white finish to the castings. It can be used for making figurines, statuary, picture frames, life castings and even restoration works. All castings will turn out detailed, strong and durable. Enjoy the smooth plaster surface finish in the casts and life casts!

Working with Mold Making Latex Rubber

Latex rubber molds are easy to make, economical, last for years and can be used for multiple castings. Following are a few pointers to be kept in mind when making a latex mold through the brush-on method.

Latex rubber is considered the best material for making molds – it trumps in terms of affordability, durability, reusability, convenience and more. The molds turn out flexible and can be used to capture a negative impression of statues, figurines, plaques, life castings, etc. The most complicated models can be easily captured down to the minutest details.

In fact, latex is formulated in liquid form to allow ease of use for making molds. Take Kreemtex Premium Liquid Latex for Mold Making for instance. The liquid rubber can be brushed, sprayed or poured over the model to capture its shape in a mold. The thick consistency makes it easy to apply and also allows for easy coverage with minimum coats. However, if the rubber seems to be too concentrated, it can be thinned to a more viscous consistency by adding distilled water to get the requisite runniness.

Latex rubber should be stored in a cool place; it should not be allowed to freeze as this will make it unusable. It should be stirred properly prior to use. In case the ammonia content of the latex has evaporated or diminished over time, it is better to replenish the same before use. However, the ammonia should come from a chemical store and not grocery ones as the latter contain more of soap. Add a bit of ammonia at a time till the original texture is obtained.

How to apply?

Brushing multiple coats of latex over the model is the most common method of making a latex mold. Some models may have to be sealed prior to late application. Applying a suitable release agent is preferable.

Start from the top of the model and brush the latex in a thin and even coat while making sure that all air bubbles are brushed out. From the bottom, continue out to form a two inch flange which will serve handy when using the mold for casting.

Allow each coat to dry properly – it should be dry to the touch - before starting the next one. Here it is advised to apply the liquid latex in a checkerboard fashion by alternating the direction of application. This will ensure that the mold does not shrink and the dimensions do not change. A heat source can be used to hasten up the drying between coats.

Once the desired thickness is built up (will take 10 to 12 coats at least), the mold can be removed from the model and allowed to dry further for 72 hours or so. Curing in a warm atmosphere to ensure proper strength and toughness to the mold.

Molds made from Kreemtex Premium Liquid Latex for mold making will be stable, tear resistant and can be used to cast different materials. The outcome will be perfect as long as the proper procedure and precautions are followed!

How Tough is a Cold Cast?

Making a decorative metal piece does not have to be pricey and cumbersome. Cold casting makes it easy, but artists should keep in mind that the reproduction will definitely be more brittle than metal.

Cold casting is a popular method of making faux metal casts. It involves mixing metal powder with a resin to create castings that give the appearance of solid metal. Rather than the hot casting method using molten metal in a foundry that is both expensive and time-consuming, cold casting turns out to be a quick and affordable option for recreating the look of metal casts. There is no risk of burns and other dangers either.

Recreating a figurine, prototype, hardware pieces, small run production pieces and other parts with cold casting is relatively easy. The requisite bronze, brass, copper, steel or aluminum powder is usually brushed, dusted or sprayed on the inside of the mold to form a thin and even coating. Then the resin is mixed and poured into the mold. (For smaller pieces, the powder can even be mixed in the resin itself.)

Once the resin is cured, it is demolded and burnished or abraded with steel wool to remove the binder and reveal the beauty of the metal filler on the surface of the cast. Keep in mind that when the metal powder is mixed with resin, it may take a bit longer to cure.

The same technique can be used to recreate the look of ceramic, wood or even stones like granite, marble and limestone. Tin powder can work well for achieving a pewter, iron or nickel silver finish.

Points to ponder

While a cold cast sculpture will replicate the exact look of the original metal, stone or wood piece, it will obviously not weigh the same. It is much lighter and some artists retain the light feature as it makes the ‘sculpture’ easier to handle. Otherwise the mold can be backfilled with fiberglass, iron or steel shots, sand or calcium carbonate to achieve the desired weight. Alternatively, the cold cast can be lightened by adding hollow glass beads.

Coming to the durability of the cold cast reproduction, it will definitely be hard and durable. The actual toughness will depend on the casting resin used to make the piece. All resins cure hard and epoxy resin is considered exceptionally sturdy. However, the strength and durability of a molten-crafted metal construction cannot be replicated. Therefore, care is required not to bang or drop the cold cast figurine.

The best choice

EnvironMolds offers a variety of fine grade cold casting powders that are 325 mesh grade - the correct fineness for cold casting - and can recreate a beautiful finish. Even the resin options are of top quality and will turn out strong and sturdy castings that can last long as long as they are handled properly.

In sum, cold casting with casting powders is the way to go to get the desired effect without spending a bomb or even bearing the risks of a foundry casting.

Clay Goes from Modeling to Ballistic Testing

Clay is as versatile as a material can get. Get to know the different uses of various types of clay that ranges from clay models, molds and casts to even ballistic testing of vests and varied weapons.

Clay enjoys wide patronage in the world of mold making. Clay modeling is very popular and is used for a variety of purposes. Apart from molds, this extremely malleable substance is also used for sculpting, mask making, special effects, animatronics and claymation. The best part about using Plastilina clay is that it is oil-based and non-drying. This makes the material reusable as well.

Apart from this, clay proves to be handy for various other unexpected uses too. For instance, small dabs of clay are used to affix the model to the base before making the mold. The same clay can be also used to fill the gaps around the edges of the model; this will give a good, clean edge to the mold. Even any spaces or holes in the model can be plugged with clay before applying the mold making material. It also serves well for sealing the edges of the mold box, so that the mold material will not seep out before it cures on the model.

Other types of clay

There is a special type of clay called ballistic clay. The distinct feature of this clay is that it manages to almost replicate the density and viscosity of human tissue. The close match makes it useful for estimating and comparing the destructive effects that various firearms and ammunition can have on the real human body.

The gel like substance is regularly used as a backing material for terminal ballistic testing – like the testing of ballistic vests. It will provide unmatched terminal ballistics data for all types of rifles, handguns, machine guns, muzzle loaders, air rifles and pistols, bows and crossbows. In addition to this, ballistic gel heads and torsos can be used to simulate the effects of various bullet wounds with reliable and consistent results every time.

Where to get them?

EnvironMolds stocks a fine selection of plasticine, ceramic and ballistic clays of all types and price ranges. The renowned choice of professionals – Roma Plastilina clay comes in several degrees of hardness and is suitable for almost any application. Then there are budget options from Del Milano and even sulfur free formulations from Chavant. The latter can be used to cast silicone rubber without any fear of interfering with the setting of the rubber.

Coming to ballistic clay, the art supplier offers ballistic clay and gel blocks along with dummy heads and torsos. The clay is clear, odorless, reusable, 100% synthetic and contains no organic materials. It is non-toxic and can easily be molded into any shape as desired. More importantly, it is completely temperature stable (up to 240℉) too. Moreover, Clear Ballistics does the calibration on the gelatin to ensure that each batch meets the FBI protocols for ballistic testing.

Learning the Mold Making/Casting Lingo

What is the negative image of a model called that you will make before making a positive replica? What are the holes on the top or bottom of a mold called? Know the terms that go with molds and casts right away!

The world of mold making, casting and life casting comes with its own plethora of terms and phrases. Familiarity with them is essential.

  • Mold – It is a negative impression of the model, usually in the form of a hollow cavity.
  • Cast – This is a positive duplicate of the model which can be in any other material or color as desired.
  • Cold cast – This is a faux cast – it is made of resin but can duplicate the look of metal, stone or wood.
  • Life cast – The three-dimensional representation of a live person – it can be the face, hands, feet, torso or entire body.
  • Pot time – Also known as working time, this is the time on hand to work with a material – it includes the mixing and application time - before it will start to set. After this, the material will not work properly.
  • Cure time – This is the time that the material will take to get completely cured. It can range from just a few minutes to hours or even a few days.
  • Shelf life - The period of time a material can be stored and remains suitable for use.
  • Mix ratio - The proper proportion (either by weight or volume) of material and catalyst (oftentimes referred to as Parts A and B) to be combined.
  • Shore hardness – This is a measure of the hardness of a given material or how resistant it will be to permanent indentation.
  • Release agent – A material applied in a thin layer to the surface of the model or mold so as to allow the subsequent mold or cast to be demolded easily.
  • Sealer – Another material that is applied on porous models to seal the pores and prevent the mold making material from getting absorbed.
  • Demolding – The process of removing a model or casting from a mold.
  • Parting line – A marking line which denotes where the parts of the mold should meet.
  • Keys – These are created at the ends of multi-part molds to join the different parts together to form a complete mold.
  • Spues – These are the small holes which will help release the air trapped inside the mold.
  • Pour hole – This is created as an opening to allow the casting material to be poured into the mold.
  • Viscosity – This is the thickness or thinness of the material and will dictate how easily it will flow. Less viscous materials are thinner and flow easily.
  • Pressure pot – Resins are usually cast under pressure that will compress the trapped air to miniscule size.
  • Vacuum chamber – The rubber mix is usually churned using a vacuum pump with vacuum chamber. The vacuum chamber will suck out the air and not allow bubbles to appear on the rubber mold or cast.

Armed with this detailed knowledge, get going right away!

Poured Block vs. Blanket Molds

Molds can be made by different methods - some simple, others more complicated. Each technique has its own pros and cons and the choice will depend on the preference and dexterity of the artist.

A mold is the easiest way to reproduce just about anything. The mold is nothing but a negative copy of a model that captures all the surface details, right from size and shape to undercuts and indentations. This is used to make original copies that are also known as casts.

How to make a mold can seem quite intimidating at first. However, mold making is actually quite an interesting and fun activity. There are very many materials that can be used to make the mold with an equally varied array of techniques for making the mold. A block mold is the easiest method that is usually preferred by beginners while the blanket molds can get quite complicated at times, especially if the mold has to be made in parts.

Following is a look at the primary differences between a poured block mold and a poured blanket mold:

  • Making a poured block mold is quite easy and quick whereas a poured blanket mold can take quite some time and effort. The latter is an intricate task involving making a pour hole and spues which requires some practice to master.
  • Both types of molds call for some form of containment. A block mold is made in a mold box – a suitable container will also suffice here. Furthermore, it is quite easy to make a mold box from scratch too. On the other hand, a poured blanket mold entails the construction of a mold shell. This is again quite complicated, time-consuming and needs practice.
  • Poured blanket molds generally require less mold rubber than poured block molds. It can take three times or even more quantity of rubber to fill the mold box containing the model when making a poured blanket mold. The mold making space is quite restricted (between the model and shell mold) in a poured blanket mold and require very less material. Therefore, poured block molds turn out be much more cost-intensive which can prove to be a limiting factor.
  • A poured blanket mold is usually thinner and more flexible. This makes it much easier to demold a casting from a poured blanket mold than from a poured block mold.

This is why artists usually begin with the block mold method and with practice, move on to the poured blanket technique.

When looking for mold making materials to make either a block or blanket mold, do not forget to check out the array of options at EnvironMolds. The website is quite a treasure trove for mold makers and casting artists with its massive collection of materials, supplies, tools and equipment for making molds and casts. It even doubles up as a teacher and guide on mold making and casting by offering blogs, books, CDs and other instruction materials choc-a-bloc with handy tips and other useful information.


The Best Rubber Material for a Mold

The making of rubber molds throws up three different options of latex, silicone and polyurethane rubber. Understanding the properties and usage will help in choosing the right rubber for a project.

When it comes to making rubber molds, there are various options, from the natural latex rubber to synthetic compounds like polyurethane rubber and silicone rubber.

One of the first steps when making a mold will be deciding which rubber to use. While each has their own strengths and weaknesses, the choice will determine the process ahead. Let us take a look at each option –


Latex rubber is one of the least expensive mold making materials. Yet, it is very flexible, strong, durable, tough and tear resistant. It also captures minute details very well. As the rubber is viscous enough to not run off vertical surfaces, it can be applied to models such as architectural details where they are, without needing to be thickened.

Latex molds can be used to cast plaster, polyester resin, urethane or even abrasive materials like concrete. The molds can be used again and again to produce multiple castings. They will literally last forever as long as they are stored properly.

However, it takes a long time (around 10 to 15 days) to make a latex mold. It involves brushing multiple layers of latex on the model, while allowing sufficient time in between for every layer to dry properly.

The rubber works well for creating masks too. Moreover, liquid latex is a theatrical and special effects product used to create wrinkles, scars, gashes and as an adhesive for bald caps.In a less viscous form, the same material will work for casting purposes as a latex casting rubber too.


This is a high strength rubber with excellent chemical resistance. It opens up options of varying consistencies and even a choice of firmness for the mold – from soft to medium to hard. The cost is on the average side – neither too expensive nor very cheap.

Polyurethane rubber molds are most suitable for casting polyurethane, epoxy and polyester resins. The method of making the mold is not limited to brushing or spraying; polyurethane rubber can even be poured to make solid cube molds. The mold will be ready in a few hours or a day at best.

However, polyurethane molds are not as long lasting and can even lose their shape over time.


This is an expensive material, but the superlative properties and ease of use justify the price. It is a versatile, durable and highly resistant rubber with two types of catalysts – tin and platinum – that will affect its working and usage.

The rubber is formulated in varied types with food safe and skin safe options also available. The translucent variant can perfectly duplicate skin surfaces. The best part is that silicone does not stick to anything but itself, negating the use of a release agent.

Silicone rubber can be used to cast different types of materials except itself. Again, the same rubber can be used to make castings too.

Consider all factors of mold making to make the right choice between liquid latex, polyurethane and silicone rubber.

Types of Silicone Rubber

There are many basic differences between liquid silicone rubber, room temperature vulcanizing silicone and the high temperature vulcanizing variant which influences their potential use.

Silicone rubber is a man-made elastomer that is composed of silicone with carbon, hydrogen and oxygen. This inorganic rubber-like material is used extensively across various industries - rail, aerospace, automotive, food/beverage and artworks to name a few. The superior benefits of resistance to high temperatures, weather and abrasion coupled with chemical stability and electrical insulation make it a popular and commonly-used rubber for varied applications.

It is manufactured in three different forms with varying viscosity and curing temperatures:

  • Liquid Silicone Rubber (LSR) – As the name goes, this is in liquid form with good viscosity and flows well. It is a two-part silicone and the curing occurs only when the base material comes in contact with the catalyst. This is a thermosetting material and cannot be restored to its original form after curing. The range of hardness is wide, from 5 to 90 Shore A. The excellent liquidity ensures that the rubber can easily fill the most complex parts of the mold, making it perfect for automated injection molding, compression molding, transfer molding and other molds that have complicated designs or demand tolerance.
  • Room Temperature Vulcanizing Silicone Rubber (RTV) – This rubber is also in liquid state, but comes in both one-part and two-part formulations. The two-part variant is again of two types - condensation cure and addition cure. The former uses tin salts as a catalyst while the latter relies on a platinum-based catalyst to turn the liquid silicone into a solid form. It should be noted that these types of RTV silicone rubbers are not only quite different from each other, but also not even compatible with each other. However, all RTVs will cure at room temperature when they come into contact with air.

In general, RTVs cure to a soft or medium hard finish ranging from 15 to 40 Shore A. They have low shrinkage and can capture details well, making them suitable for injection molding, gravity casting and vacuum casting. They enjoy varied applications including mold making, casting, prototype-making, prosthetics and encapsulation. The tin-cured silicones have food safe, skin safe and transparent versions too.

High-Temperature Vulcanizing Silicone Rubber (HTV) –
This is also known as Solid, Milliable or High Consistency Silicone Rubber. It is usually in the form of solid, gummy rubber blocks which are partly vulcanized, though liquid forms are also formulated. It goes without saying that the rubber has to be heat-cured at high temperatures to get the finished product. It is used for compression and resin-transfer. Silicone tubing and other shapes are often extruded from HTV silicone rubber.

EnvironMolds offers a great selection of high quality RTV silicone mold rubbers that can be used to make a silicone mold or cast. This popular art supplier also provides skin-safe, food-safe and translucent silicone rubber formulations. Apart from this, other related materials, supplies, tools and equipment are also available.

Embarking on the Journey of Life Casting

Life casting is not easy, but it is not rocket science either. Knowledge of the materials, the process and the application is essential, but you will not get the hang unless go ahead and give it a stab.

Life casting is a wonderful art that has captured the imagination of many an artist. While experienced and accomplished artists seem to easily create spellbinding life casts without breaking a sweat, fact of the matter is that making body molds and life casts is quite a complicated and painstaking process. It calls for working with care and precision while paying attention to minute details. Knowledge of the various materials, their properties and other factors is also essential. And the artist has to be particularly alert as he/she will be working on live models and cannot afford to harm/trouble them in any manner.

However, this does not mean that novices cannot try their hand at life casting! Following is what a beginner needs to know/do:

  • Different materials and supplies are required for making the body mold and life cast. Alginate is a natural material and can be safely used on the model; skin-safe silicone rubber is also a good option. A release agent has to be applied first and the mold has to be reinforced with a shell mold of plaster bandages.
  • You have to acquire the know-how about the various processes like how to properly mix the mold making material, apply it on the model, demold the body mold, pour the casting material, finish the life cast and so on. This can be learnt from instruction guides, tutorials or attending live workshops. Small tips and tricks from expert artists – like making the face mold with the model lying down, using soft water for mixing alginate and twitching the body to remove the mold - can make a world of difference.
  • Prepping the model is a crucial step of the life casting process. The model has to be informed about what lies in store, how to hold the pose, warning signs and so on.
  • You will never feel you are completely ready, so just go ahead and jump in. Do not be afraid to get your feet wet as theoretical information can only go so far. And there will definitely be loads of mistakes on the way. Try and try and you will definitely succeed very soon. In fact, both experience and perfection comes from trying.
  • Life casting is a messy job. Be prepared to get your hands dirty. Once you get the hang of the process, you will start enjoying it and even become proficient at it very soon.

In general, there are different materials and varied techniques for mold making and casting. Body casting and life casting follow most of the same principles, but it gets complicated by the fact that you are working on a real person and not an inanimate object. This is why many artists prefer to start with regular mold making/casting and then move to life casting!

The Ins and Outs of Plaster Bandages

 Plaster of Paris is a common material that finds usage in construction sites, orthopedic chambers and art studios. When plaster is infused into gauze, it forms the very resourceful plaster bandages.

Plaster of Paris is a quick-setting gypsum plaster that comes in the form of a fine white powder. It forms a paste when mixed with water and when allowed to dry, it will take a solid form. The name plaster of Paris comes from the abundant gypsum found near Paris that is used for the preparation.

This is commonly used as a building material to form a protective coating on walls and ceilings apart from giving aesthetic finishing touches. The same plaster powder can be used to immobilize joint or limb fractures. In the medical field, it is applied as a slab, splint or full cylindrical cast on broken bones by orthopaedics. It dries to form a rigid cast that will hold the broken pieces of the bones in place and help them to heal. Dentists also often use plaster to make molds of the teeth to be replaced.

But not many people may be aware that woven fiber material (like gauze) can be soaked in a plaster solution and then dried to produce Plaster of Paris bandages.


Plaster bandages are usually used to form shell molds over flexible molds – like those made of alginate or silicone rubber. It forms a stiff covering that helps the mold retain its shape and the firm mold can then be used for casting purposes.

Apart from this, the bandages are also directly applied on both living and non-living models to make form molds. This will capture the basic shape without the finer details. Therefore, it is usually used for making belly molds (like pregnancy casting) and other basic shaped figures.

How to use?

Plaster bandages are fast and practical to use. The reverse process comes into play here – just soak the bandages in water and the moistened bandage will be ready to use. The bandages will harden rapidly, to form a resistant structure which does not lose shape.

Roll out the bandage and cut into the required lengths. Take a bowl of water and soak each bandage for a couple of seconds before squeezing it gently. Then apply on the required surface. Smooth it out with the fingers while ensuring that air bubbles do not get trapped inside.

Where to find?

EnvironMolds offers a complete array of materials, supplies and tools for making molds, casts and life casts. This includes top quality plaster bandages at very reasonable prices. The bandages are skin friendly and smooth. They offer rapid plaster immobilization with quick water absorption that enables faster application on the molds or even the body. There is appreciable mold ability which allows it to conform properly to where it is applied, thus facilitating easy and accurate molding.

What’s more, the same bandages can also be used in the medical arena to form plaster for bone and joint fractures.

Tips for Working with Materials

Mold making and casting is an easy job as long as you abide by the rules and instructions. Following are some useful tips that every artist should follow, irrespective of the type of mold or cast.

The world of mold making and casting opens up a veritable treasure trove of materials – each with their own specific characteristics, methods and usage. The commonly used options are clay, wax, alginate, moulage, plaster, gypsum, concrete, polyurethanes, rubbers, etc. Artists can try their hand at different materials and play around with different options depending on the type of mold or cast they are making.

Following are some general tips that beginners should keep in mind when working with almost any kind of material for making molds or casts:

  • Every packaged material comes with its own set of product literature like TDS (Technical Data Sheet), safety data sheet. Always read the label and other product information carefully before using the said product.
  • Work with materials that are already at room temperature and ensure that the room is at room temperature as well.
  • Stick to the prescribed methods and techniques – like mix ratio, type of release agents, compatible materials – at all times. At times, there may be other simple provisions that can make a world of difference. For instance, alginate requires the use of soft/bottled water; using hard water even unintentionally will render the material into a lumpy mess. It takes experience to deviate from the given methods to tinker with the viscosity or other features.
  • Some materials are suitable for certain applications and other options may not work as well, depending on the model, mold-making/casting material and other factors. Choose an appropriate material for the task. Seek advice from experts if needed.
  • Always shake or stir components thoroughly before use. Sludge can sit at the bottom of the box while oil tends to float on the top. Shaking before use followed by proper mixing of the components together is crucial.
  • Always mix a small amount as a batch test at first. It is better to get a feel for the material before mixing in large quantities for the project as it can end up as a time-consuming and expensive mistake.
  • First try your hand at making a small mold or casting, use a small object as a test model before moving on to larger molds or castings.
  • Keep the pot time and working time in mind. Avoid pouring delays as this will add to the working time and can affect the quality of the mold or cast.
  • Before pouring, check if the sealer and release agent have been used, if required. Also check the mold/mold box for leakage before pouring the material.
  • Wear gloves when working with any materials. Some materials may require the use of mouth mask, safety goggles and other additional protection.
  • Use clean and good tools for any project. Assemble the required tools and supplies before starting the work.
  • Follow the indicated set time and demold time to the T. Else, the mold or cast will end up distorted/deformed and unusable.
  • Do not hesitate to ask any questions to the experts about the clay mold, resin casting, cold casting, alginate life casting, etc.

All the best for your new project!

Silicone Rubber - Different Faces and Usage

Silicone rubber is a versatile material that is used for different purposes in both the art and manufacturing world. It displays many useful properties and comes in a few different types too.

Silicone rubber is a popular compound that enjoys widespread patronage across industries and applications. It is commonly used for bonding, sealing, potting, encapsulation, coating, mold making and casting works.

The main benefit is that silicone rubber molds that can be used for manufacturing different types of technical and mechanical parts for industry and medical devices. Apart from molds, silicone rubber is also used as a release agent, adhesive or the base material for the cast. It also functions well in the potting of electronic components in high-tech industrial and scientific equipment.

Artists normally use the rubber to make molds for toys, candles, soaps, food and baking containers apart from special effects. There is a special variety of silicone rubber that is safe for the skin and is used to make body molds.

The same rubber can be used to make casts too and is the material of choice for mask making and doll reborning.

Getting to know Silicone Rubber

RTV silicone rubber is commonly used for molding and casting projects. It delivers various useful properties like ease of use, flexible, tough, durable and tear resistant. This versatile material can reproduce almost anything without damaging the surface of the model. What’s more, the excellent mechanical properties and low surface tension enable it to replicate the mold without losing any of intricacies of the original - the minutest of details will be captured in the mold even down to the skin pores and fingerprints. It can even be cast in abrasive materials.

Silicone rubber formulas are remarkably stable in a wide temperature range and prove to be non-flammable and non-combustible. There is a good level of thermal conductivity too.

The room temperature vulcanizing rubber comes as a 2-part formula – one is the liquid base and the other is the catalyst. They have to be mixed in the specified proportion which can vary from formula to formula. The catalyst will react with the base to deliver the intended properties. It can even be customized to produce the required degree of viscosity and adherence along with varying mechanical, chemical or temperature resistance characteristics.

The rubber comes in two different types – addition cure and condensation cure. The primary difference is in the catalyst - Addition cure silicones use a platinum-based catalyst (usually 10%) while condensation cure silicones need a tin-based catalyst (usually 5%). They have different characteristics and usage and most importantly, are not compatible with each other.

EnvironMolds offers a broad range of materials, supplies, tools and equipment that include both silicone mold and casting rubbers. There are different formulae options to suit varying needs and preferences, like MoldRite 25 Silicone - Classic Mold Making Silicone, BluMold RTV Silicone, 5-Minute Mold Putty for Faster Mold Making, Food Safe Silicone -- BakeSil FDA Approved, LifeRite Skin Safe Silicone for Life Casting and SkinRite 10 Translucent Special F/X Silicone.

The Ins and Outs of Latex Rubber

Latex rubber is an artist’s weapon that can be wielded in varying manners. The properties and versatility of liquid latex rubber are to be experienced to be believed. Let’s find out more about this….

Liquid latex rubber is a versatile product that lends itself well to varied applications. The wonderful part about the rubber is that it is suitable for making both molds and casts. Changing the viscosity will change the application – latex molds require more thick and viscous formulations than casts. The degree of flexibility of the latex can be further controlled by adding an appropriate filler during the casting process.

Latex mold rubber is commonly used for mold making as it is economical, durable and easy to use. The molds will be tough, tear resistant and can be reused multiple times. They are used to cast plaster, polyester resin, urethane and even abrasive materials like concrete.

On the other hand, the casting variant of latex rubber is used for making hollow molded rubber articles like toys, balls, props and even display articles. It enjoys great patronage for making masks, puppet heads and even special effects like wrinkles, scars and gashes for theatrical work.

Latex rubber can be brushed, sprayed, poured or dipped for making the molds and casts. Brushing requires successive coats and sufficient time should be allowed for drying between each coat. This process is continued till the desired thickness is obtained. Spraying will also involve a similar process.

Latex is usually cast in plaster molds because of the porous nature of plaster. When the rubber is poured into the mold, the plaster sucks the water out and leaves a thin latex skin behind. Slip latex casting is a commonly preferred method as it is comparatively easy and does not leave any brush marks either.

When it comes to demolding the latex mold or cast, an easy trick is to dust the latex with talcum powder before peeling it off slowly. The powder will keep the fresh latex from sticking to itself. The latex mold will need to be supported before casting so that the flexible rubber can retain its shape.

Latex rubber is also used to form a protective coat on different items. The latex coat can make fabrics waterproof. It can also form a protective covering on tools that will provide a sound and comfortable grip even while insulating them against electrical hazards.

The most common use of latex rubber is for making a latex mask. This can be used for special effects in movies or even a fun element for Halloween and other occasions. It is usually cast in a face mold made of plaster bandages and then the desired characteristics are built on it step by step.

Other tips to keep in mind when working with latex rubber is that it contains a good amount of alcohol. Proper ventilation is required and do not inhale it too deeply or frequently. Similarly, the rubber will become unusable if frozen. Store it carefully in the winter months of the year.

The Fiber-Reinforced Version of Alginate

There are alginates and then there is fiber-reinforced alginate. This comes with greater tear strength and delayed shrinkage which makes it ideal for larger life castings as well as for special effects works.

Alginate is the material of choice for making body molds. This is a natural compound that is actually derived from seaweed and is used to make dental impressions. Its quick setting and skin safe properties make it suitable for using as the base material for life casting.

A variation of the regular alginate – with a slower set time than the dental formula – is used for making body molds. This alginate is mixed with water and the paste is applied directly on the skin. It sets quickly while capturing a perfect negative impression of the body part – be it face, hand, foot, torso, abdomen or even full body. A good quality alginate, when used properly, it will capture all the fine details and indentations of the body surface down to the fingerprints as well. Everything can then be reproduced in clear detail in the life cast.

Now alginate comes in different varieties to suit diverse requirements. The traditional formula is in the form of a white powder that contains silica and offers a firm set. Yet, it needs to be reinforced with a shell mold as the alginate will not be able to retain its shape on its own after demolding.

In case artists want to steer clear of silica formulas, there are silica-free alginates that offer a softer set and are, therefore, gentler on the skin. This is especially favored when making life casts of a baby’s hands or feet.

Both these categories of alginates come in variants of slow set, regular set and fast set, to suit varying dexterity and applications. For instance, the slower setting formulas prove to be very useful when making molds of the torso or other large body parts. The slower set ones are again preferred when working with infants.

The best type of alginate is the fiber-reinforced alginate – like FiberGel alginate. This contains fiber which not only helps enhance the tear resistance and strength, but also increases the alginate’s capacity to hold moisture. It also serves to delay the shrinkage of the alginate mold, thus giving more time for the casting process.

Therefore, FiberGel is the best choice for larger molds and actually, all life castings. In fact, FiberGel E F/X Grade Alginate (available on the EnvironMolds website, is specially formulated for professional high-production, high-end detailed E F/X work.

This FiberGel comes with a patent pending duo fiber matrix system that has been independently tested 40% stronger than the best options in the market.

What’s more, the fiber content also serves to prevent runs and drips. The alginate mix (when made using the prescribed ratio of powder and water) will stay where you put it. This makes it suitable for working on vertical surfaces too. The molds also stay soft and flexible far beyond normal alginates, thus extending the window for casting times without any loss of detail.

Correcting Mistakes in Plaster Life Casts

Errors are bound to happen at different stages of the body casting and life casting process. Here we take a look at the problems that can surface in a plaster life cast and how to correct some of them.

Life casting begins with capturing a mold of the human body and ends with a finished cast that is an exact reproduction of the model. The body mold is usually made using alginate or skin-safe silicone rubber while plaster is preferred for the life cast. The final piece is usually mounted and finished with a brass name plate.

Now there is a lot that can go wrong during the body casting and life casting process. While a lot has been written about working with alginate, let us take a look at the possible complications that can arise during the plaster casting:

Air bubbles – Like any other mold making or casting material, plaster also has a propensity to trap air that can show up as unsightly bubbles on the surface of the cast. Life casting artists are always advised to pour the plaster slowly and carefully in a thin stream from a corner of the mold. Tilting the plaster-filled body mold a bit or tapping the sides will also cause the trapped air to rise to the top and can be burst easily. However, if some bubbles still happen to appear on the life cast, they can be smoothed out with the thumb, back of a spoon or by applying some water. Some artists pop them gently with a knife and then fill the hole with more plaster. Rubbing with sandpaper will help level out the final cast.

Broken fingers – Features like nose and fingers are small and delicate when compared to the entire life cast. They are very likely to break during the demolding process – it could be that the plaster has not set enough or the artist has applied too much pressure or is working in a hasty manner. The broken part can be refastened by wetting both the edges and applying some plaster. Reposition the piece and hold it in place till it sets properly. The joint can be smoothed with a wet finger or some thin plaster.

Similarly, other distortions or squashed features can also be corrected with some careful resculpting. However, it is always better to make the corrections in the body mold itself as far as possible rather than risk disfiguring the life cast.

Rough surface of the casting – At times, the plaster surface of the casting may seem coarse and bumpy in places. This can happen due to various reasons like skewed ratio or improper mixing of the plaster. Either way, the best recourse it to smooth out the surface with sandpaper.

These techniques will work for minor errors and corrections. In case of a major blunder, it is better to redo the life cast rather than keep trying to correct an inherently flawed or inadequate piece.

And when the perfect piece is ready, it can be mounted on a marble or wooden base and finished with customized brass name plates engraved for that wonderful gallery finish!