How Many Plaster Bandages Will You Need?

 Use too few plaster of Paris bandages for making a shell mold and you will be left with a distorted mold on your hands. Tips on how to calculate the requisite amount of rolls will prove helpful.


Plaster of Paris bandages are a versatile accessory when making molds, and especially body molds. The most common use of plaster bandages is for making shell molds. Also known as mother molds, they provide rigid support so that flexible molds made of alginate, latex rubber and silicone rubber can retain their shape. The shell mold is made over the original mold so that it can house the mold and ease the casting process.

 


Apart from this, the bandages are also directly used to make form molds like the torso, belly and legs in body casting. They are also useful in mask making.

This brings us to the question – how many plaster bandages will an artist need for making a shell mold or even a form mold? Keeping sufficient rolls of bandages handy is imperative. In case you fall short during the mold making process, the mold is most likely to distort and collapse into a useless mess.

This is especially important as the bandages are built up in overlapping layers to ensure that the mold become sturdy enough after drying. Therefore, eyeball estimates by newbies can easily go haywire.

A simple rule of thumb is that the bigger the mold, the thicker should be the shell mold to ensure that it does not distort during the casting. Following is an estimate of the number of layers of plaster bandages required during life casting:

  • Face mold - 4 layers
  • Head mold - 5 layers
  • Half torso - 5 layers
  • Full torso – 6 to 8 layers


Now, a standard 5-inch roll of 5 yards plaster bandage yields around 900 square inches of bandage therefore, a single roll of plaster bandage will easily suffice for a typical face mold. A head mold will require 4 to 5 rolls and half torsos can be covered with 4 rolls. Full torso will take about 5 to 6 rolls for proper and thick coverage.

Environmolds (https://www.artmolds.com) offers a broad range of top quality plaster of Paris bandages. The creamy and smooth PopArt Plaster Bandages are available in 5 inches, 8 inches and 12 inches by 5 yards length. These are superior quality quick-setting bandages that are formulated to wet out creamy with a thick plaster consistency. They set quickly within 5-minutes itself.

Then there is the ArtBands Plaster Of Paris gauze bandages (5 inches * 5 yards) with a modern formulation that produces a consistent fast-setting plaster coat that adheres to the gauze cloth uniformly. It yields a smooth, creamy surface, is fast setting, resists delamination and gives excellent strength. The Gypsona Plaster Bandage is another premium bandage (6 inches * 5 yards) that has been the first choice of mold makers and life casting artists for over a decade.

The Different Faces of Clay

 Clay is a multipurpose material that lends itself well for different uses. From sculpting and special effects to mold making, pottery and even other rudimentary applications – clay has a lot going for it.


Clay is a soft and malleable material that can be easily molded as needed. Kneading, squashing and shaping the clay into different forms is very easy and fun as well.

This humble clay is ready to use and very versatile - it can be used for different purposes in artworks. The most popular application is obviously for clay modeling – from making sculptures, masks and even prototype models to special effects and animation too. Moreover, the clay can be used as it is for making basic molds for casting resins, rubbers or even metals. It does not require any weighing or mixing before use.

Ceramic clay is commonly used to make pottery. The earthenware is fired in a kiln and glazed to make it hard and durable.

Apart from this, clay also proves to be handy for other minor jobs. For instance, if a model has holes or spaces, it can interfere with the mold making process. Clay can be used to plug these gaps or even tunnels that run through the model. Then the mold can be made as usual, but with a different mold making material other than clay.

In fact, clay is often the material of choice for making a containment field around the model when making the mold. The clay can be built to the height and thickness as required. Even when using other materials to make the mold box, clay is commonly used to seal the edges so that the mold making material does not seep out from the gaps. It can also be applied around the edge of the base to fill the gap between the model and the base.

Types of clay


The regular water based clay is suitable for children’s art classes and playrooms only as it tends to dry and shrink quickly. The professional grade oil-based clays are preferred by artists around the world. They have the same flexibility as regular clay, but the oil content keeps it from drying or cracking even after being exposed to air. They are firmer, capture fine details and can hold the form better as well. Heating and cooling allows the artist to control its malleability. In fact, this clay can be remolded and is inherently reusable.

Another variant of non drying and oil based modeling clays ballistic clay. This is primarily used by government agencies to test body armor as it is considered to be of similar density and elasticity as live animal muscle tissue.

EnvironMolds offers a range of oil-based clay options like Chavant Plasteline clay, Del Milano Plastilina clay and Roma Plastilina clay along with regular earthenware pottery and ballistic clays. Sulfur-free alternatives are also available as the sulfur content of regular clay can interfere with the curing of silicone and polyurethane rubbers. In addition, it also has a variety of tools for carving and sculpting during clay modeling.

Release Agent for Life Casting

 Mold making and casting requires the use of a release agent for proper demolding. MoldEZ Hair and Mold Release is used for the demolding of body molds and it proves handy for other functions too.


A mold maker or casting artist needs a lot of supplies and tools to make their art come alive. Apart from the regular items, there are a few tricks up their sleeve which ensure that the mold or cast turns out perfect.

 

For instance, the mold maker will deair the resins and rubbers in a pressure pot or vacuum chamber to ensure that the mold is bubble-free. Similarly, a casting artist will use specialized paints and dyes to color the resins and rubbers to eliminate the chances of cracking or chipping later on.

Another system that these artists follow is using a release agent before making the mold or cast. This is basically a lubricant which creates a slip effect and prevents the possibility of the material fusing to the model or mold. This in turn ensures easy demolding without any unnecessary stretching or tearing. It is basically akin to greasing a pan prior to baking so as to allow easy removal of the food without any sticking. This also fulfills a dual purpose as the release agent can seal the surface of porous materials.

Likewise, even life casting artists apply a mold release on the human body so that the body mold will come off easily without snagging in the fine body hair.

It follows that the type of release agent will have to vary depending on the usage. After all, a release that is suitable for metal may create an adverse reaction when applied on plastic and vice versa. This is why release agents are specially formulated for different materials so that they don’t impact the model or mold in any manner.

The life casting artist has to be particularly careful when working on the human body – specialized release agents like MoldEZ Hair and Mold Release or simple petroleum jelly works best!

Applying the release agent


Most release agents come in cans and can be sprayed or brushed on the surface to be molded or cast. Spraying is considered better as it will create a smooth finish. Brush marks can end up reproduced on the mold or cast and look quite unbecoming. Ensuring an even coat in the specified thickness is also essential.

MoldEZ Hair and Mold Release comes as a cream formulation that can be applied on the skin. It is usually preferred for the hair as the cream can be worked in easily and then combed to create a uniform effect. It will also wash out easily the first time itself. On the other hand, petroleum jelly can make the hair greasy and will not wash off easily either.

The same material also works well for filling in any pin holes in the body mold before proceeding to the casting stage. Some artists also apply this release agent on the edges of the alginate mold to bond it with the plaster shell mold.

What Makes MoldRite 25 The Best Silicone Mold Rubber

MoldRite 25 is a popular silicone rubber formulation suitable for general mold making. The molds are easy to make and turn out to be high quality and long-lasting. They reproduce perfect details too.

Silicone rubber is a versatile material that lends itself well for making different types of molds. Moreover, the rubber is also formulated in diverse forms to suit varied purposes – there are separate formulations for general molds, food molds, body molds, mask making and doll reborning and even for making quick molds.

MoldRite 25 Silicone is a standard silicone mold rubber for making traditional molds from the house of EnvironMolds. It is favored by mold makers, sculptors, prototype artists, craft artists and other artists for making molds of candles, soaps, toys, picture frames, figurines, statuary, jewelry, plaster moldings, architectural pieces, prototyping and more. In fact, it is suitable for reproducing any item which requires high quality molds.

This is a two-component tin-based silicone formulation with a 10 to 1 mix ratio by weight. It is mixed with cat-blue catalyst in the prescribed ratio which imparts a lovely blue tint to the mold. Both the rubber and catalyst should be weighed carefully and mixed in a clean container with a flat-ended spatula till a uniform color is achieved. The silicone mix needs to be deaired in a vacuum chamber prior to use. This will eliminate air bubbles that can otherwise tarnish the appearance of the mold.

MoldRite 25 is easy to pour and has a pot life of 2 hours and working time of 40 minutes. The common procedure is to first pour a print coat over the model before continuing with the mold making. It will capture perfect details right down to the smallest undercut or indentation on the model. A release agent is not needed as silicone does not stick to anything except itself. In fact, the tendency to stick to itself comes handy as multiple coats of the rubber can be applied where needed.

The rubber cures quickly to form a flexible and reusable mold. It should be allowed to cure for 16 to 24 hours before demolding and an additional 24 hours air curing before casting. Heat acceleration is not recommended. Full cure takes 3 to 7 days.

It is advisable to maintain normal temperature and humidity as higher temperature and humidity will decrease the work life and pot life with faster cure that in turn decreases the flow time too.

The finished mold has high tear strength, is durable and reusable as well. It can be used to cast different materials like clay, wax, gypsum, polyester resin, epoxy or polyurethane resin. Actually, any material can be used for making the cast except silicone rubber.

The molds can be used to reproduce any number of casts for years to come. Proper cleaning, drying and storage after dusting with talcum powder will extend the life of the rubber mold.


MoldRite 25 Silicone can easily be sourced online from the EnvironMolds website, https://www.artmolds.com. It is available in 1 pint, 1 gallon and 5 gallon kits.

Using Liquid Latex Casting Rubber

EnvironMolds Premium Latex Casting Rubber is a consummate liquid latex formulation that serves well for varied applications. It can be used to make masks and other hollow items with different methods.

Liquid latex rubber is a popular material in the world of mold making and casting. It is tough, durable and tear resistant, apart from being an economical product. It is commonly used to make different types of molds for casting plaster, resin and other materials. The same material can also double up as a casting product, albeit in a less viscous form.

In fact, latex casting rubber is a popular theatrical product to create special effects like wrinkles, scars and gashes. It is also used to make all kinds of masks and other thin skin products.

EnvironMolds Premium Latex Casting Rubber is an exceptional casting rubber specifically formulated for making hollow molded rubber articles, toys and flexible props. It lends itself well for making masks, puppet heads, imitation pottery and display articles. It is especially useful for creating general special effects for film, television and stage work. Furthermore, the same product is considered appropriate for coating and texturing foams such as polystyrene, especially for special effects applications.

The liquid nature of latex casting rubbers makes it very easy to use. Pouring or painting are the common methods of making latex casts. All it takes is successive coats of the latex over or inside the mold to make the hollow or thin skinned rubber items. It is useful for making gloves, fake food and other such items.


On the other hand, artists usually pour the latex casting rubber directly into the mold. The mold is filled till the brim and the latex is allowed to sit for some time post which the rubber is poured back into its original container. A thin layer of latex clings to the sides and base of the mold. This sets like a skin overnight and can be demolded easily. This method is commonly used for making masks.

Apart from this, you can also simply dip the mold into the latex to form a coating. Each coat has to be allowed to dry before dipping again to build up the required thickness. In fact, EnvironMolds Premium Latex Casting Rubber serves well for dip casting and can be used to form a protective coating on tools.

These latex casts cannot be finished with regular paints as it will tend to chip, crack or peel away. Special latex paints and dyes are available. These can be added to the rubber before starting the casting process or painted on the cured surface later on.

Moreover, you can also use a filler and extender like RubRfil to control the level of flexibility of the latex rubber cast. In case the liquid latex is too viscous for a particular application, mixing the requisite quantity of RubRfil will thicken the rubber and render it less flexible, hard or even very hard. This also serves to extend the quantity of the material.

EnvironMolds Premium Latex Casting Rubber, RubRfil, latex pigments and other materials can be easily sourced from https://www.artmolds.com

How To Make A Front Torso Cast

 Making a front torso cast can seem intimidating at first. However, it is the easiest life casting that can be tackled by beginner life casting artists as well. Let’s find out what lies in store….

A front torso casting can seem like a tall order because of the bigger dimensions involved. However, this is one of the easiest life castings as the body surface from neck to mid-section will be broad and mostly even, with hardly any undercuts. In fact, novice life casting artists often prefer to begin with torso casting before moving on to more complicated life casts like face and full body.


Yet, care is required when working on a living, breathing person. The model should be carefully briefed about what lies in store and warned about the issues like staying stationary, application of mold material, mold getting entangled in the body hair, waiting for the mold to set and so on.

The key to making a good torso cast lies in the posing. The model has to pose in a standing position, preferably propped up against a board or the wall for support. The pose can be a slightly leaning one to reveal the muscle tone, arms spread-eagled or on the sides of the waist. Women usually prefer to pose with hands on their breasts or encircling the belly in case of a pregnancy casting.

Once the model has been prepped, the body mold making process begins with applying petroleum jelly or other release agent all over the torso. Then apply a couple of layers of the alginate mix to form a thick and even coat. This alginate is skin safe and will not harm the model or the artist. It sets quickly and will capture all the fine details as well.

Once the alginate mold has set, it is covered with plaster bandages. The bandages are soaked in water and squeezed before applying on the alginate mold in a crisscross fashion. This will form a shell mold that supports the alginate and helps it retain the shape.

Allow the plaster mold to dry properly. Once it has set, the body mold can be easily demolded by loosening the edges with the fingertips. It will lift away easily and can then be cast with plaster or other choice of casting material. The casting should be done quickly as the alginate is likely to shrink on exposure to air.


There is a choice of making faux metal or stone life casting also by using the appropriate cold casting powder along with the casting material.

In sum, it is pretty easy to make a front torso life casting. It will take time and patience, but the artist will get better with practice. For further ease, EnvironMolds offers the comprehensive Front Torso Casting Kit. This contains the appropriate quantities of alginate, plaster powder and plaster bandages along with mold release, gloves, sandpaper and a handy instruction booklet as well.

The website, https://www.artmolds.com also throws up a helpful ‘How To Create A Front Torso Casting’ book. This how-to manual provides necessary instructions about the materials, preparations and techniques as well as tips for preparing the model, demolding and finishing the life cast. A model release form is also included.

Eliminating Estimation in Material Calculations

Why should artists rely on guesswork about the quantity or volume of materials required for making a mold or cast? EnvironMolds provides a Volume Calculator that throws up the exact amount needed.

There’s a lot of planning and coordination that goes into making a mold or cast. The artist has to not only choose the most suitable technique and material for making the mold/cast, but also assemble the requisite mold making or casting materials, supplies, tools and equipment.

 

For instance, making a block mold with silicone rubber will require plastic cups, gram scale, mixing sticks, electric mixer, mold box, release agent, glue gun, vacuum chamber and pump, gloves, knife, silicone rubber, etc.

While the artists pay careful attention to the requirements and collect the items before commencing the project, they rely on eyeball estimations for the amount of material they need to purchase or mix. For instance, if the artist mixes much more silicone rubber than actually required, the extra rubber will have to be thrown away – a sheer waste of money and resources. And if the rubber falls short, it will entail extra work of mixing more material or even rushing to the store to buy some more. The delay can even cause the artist to leave the project midway or if continued, mar the quality of the mold.

Newbie mold makers and casting artists are especially flummoxed about the amount of material they should use.

EnvironMolds comes to the rescue with a handy volume calculator on its website https://www.artmolds.com/volume-calculator. All the artist has to do is measure the dimensions of the mold box and model before feeding them in the calculator. A square or rectangular box requires the height, width and depth while cylindrical ones need the radius and height. The same rule applies for rectangular and cylindrical models respectively. Undercuts in the model can be ignored and the maximum outside dimensions will do.

This will throw up the net volume of the box, the model and finally the material needed. The calculator goes a step further and converts the net volume into the exact amount of rubber, plaster or resin required in grams or fluid ounces, as applicable.

For those who are looking for more detailed information on how to make molds and casts, EnvironMolds provides instructional books, videos, website links and blog posts as well.