Chapter 1: The Matrix:
Selecting and/or Creating Lifecasting Containers.

A matrix is any fairly rigid container which holds the liquids until they turn solid. The matrix also determines the amount of materials a particular project will need. This chapter explains how to select or construct one.

"Mother Mold" is another term for the matrix but usually refers to a free form, rigid casing or wrapping that conforms to the shape of an interior, flexible mold (the "daughter" mold). These are discussed in Chapter 3.

Containers for use in your projects can already exist or be made to fill a particular need. Follow these suggestions in your selection of an existing container:

1. Avoid metal, glass and ceramic containers since it is very difficult and dangerous to remove the finished casting from these materials. Flexible or disposable containers are best.
2. Select a matrix to fit your project. If the container is too big you will have to mix more material than necessary which is more expensive. Also, especially in Precision LifeCasting™ (Chapter 5) where working time is limited, the greater the quantity needed to fill the matrix the more frantic your efforts will have to be.
3. One way of conserving materials is to select a matrix with rounded bottoms and/or sides. Square shapes are sometimes needed but, require over 30% more material since the corners must also be filled (see illustration).
4. Many consumer product packages are perfect for LifeCasting™ and for the same reasons; manufacturers want to conserve materials and frequently use molding technologies to form their packages. Here are a few examples;
• Cylinders used for oatmeal, drink powders, etc. fit the human body very well because we, of course are cylindrical! Save these packages when empty and use them again for LifeCasting™ before discarding.
• Paper and foam cups come in all sizes from tiny medical ones to enormous popcorn tubs. Good sources are restaurant supply stores and movie theaters.

• The oval shaped, vacuum formed domes which cover whole, roasted chickens are perfect for Precision LifeMask™ uses.
• Flexible food storage containers come in almost infinite shapes, many which fit the odd forms and angles of the living anatomy.
5. The tapered shape of many such containers is because of the requirements of high volume production technologies and is ideal for LifeCasting™. Tapered containers are smaller at one end than the other. Their shape allows you to pour the fluid ArtForm™ or Earthium™ (f/x) in, do the LifeCast™ then simply turn it over to pull out the mold and unveil. If you are careful they can even be reused. Making your own matrix is sometimes the only way to get the shape you need.

One useful way to make a LifeCast™ matrix is to form the general shape from a hardware wire screen, the kind with about 1/4" grids that can be bent. Then the outside is completely covered in a few layers of plastic food wrap until it will hold water. This shape can then be bent into the exact shape.

Making A Reusable Matrix:

A Re-usable Matrix can be made with a little ingenuity. Remove the lid from any typical, cylinder-type container and cut the bottom part in half. Hinge one side so it will open and close like a clam shell as shown.

Reusable Matrix

The open side can be temporarily sealed with duct tape long enough to do a LifeCast™. When finished, remove the tape and unveil your sculpture.

Using The Custom Matrix:

To carry the above arrangement one step further, it is also ideal for making 2-part molds (See Chapter 3) for LifeCasting™ inanimate objects. The fact that solid ArtForm™ does not stick to additional amounts of fluid ArtForm™ makes these quick and easy. Earthium™ (f/x) can be made to stick to itself or not, at your discretion so it will also work with this set-up.

1. First seal off half of one end of the matrix with tape and fill that half with liquid ArtForm™ or Earthium(f/x)™ as shown below.
2. Cut some gouges into the surrounding surface of the solid mold at least 1/4" away from the object to form the "female" portion of notches to align the mold halves later. These are also called "registration bubbles".
3. Close the "clamshell" and seal it with more tape. Stand the assembly upright and pour the second half of the mold in a vertical position. The liquid will surround the object and flow into the registration notches, forming the "male" portion. Wait for this half of the mold to set.

Custom Matrix

4. Remove the tape and gently pull the two halves apart. You may have to use a straw to blow air around the object to release the suction. Take the object from the mold.
5. Re-align the halves by fitting the male protrusion into the female intrusion so they are in registration. Tape shut again and pour the casting. There will be some touch up along the parting seam required on the finished piece.

The Shell Matrix:

Shell Matrix: Is another way to create your own matrix. They are formed after using a paste application of the mold medium, ArtForm™ or Earthium(f/x)™ at a thick ratio (ie; 1:1). The mold sets and is then covered with a thin shell of ArtCast™ cement alone, reinforced by hemp fibers or burlap or plaster bandages alone.

The Shell Matrix:

This shell can be salvaged for reuse after the first LifeCast™ is poured. This is described in more detail in Chapter 3 with a specific example for doing this on faces in Chapter 5.

Slip & Slide:

This happens in slippery containers, particularly at thin ratios and in a long or deep LifeCast™. It is crucial anytime you want to make sure a matrix set up will work as intended. The mold is flexible, right? If your design is made of a hand for example, when the hand is removed most of the empty space in the mold will be where the fingers were - at the bottom. All the weight of the mold is above the fingers and, if not firmly bonded somehow to the matrix the mold will slide down, compressing the finger areas. This results in a flattened LifeCast™ in that area when the cement is poured.

Slip & Slide:

To prevent this make sure to glue something rough inside the matrix. Burlap can be used or, my favorite is the self adhesive Velcro® strip (shown in blue). Both the hook and the loop sides work fine. Attached them every few inches all around the inside of matrix. Also notice that the matrix in this illustration is an inverted taper, with the wide end at the bottom where the most space is needed. This arrangement not only reduces the amount of medium needed but, reduces the weight above the fingers as well.

Dip & Dunk:

You must remember how fluids, like air bubbles and air traps work (see LifeCast™ Basics). Air bubbles will also gather or be caught on the undersides of the object and "pool" in any concave recesses. If you simply dunk a cupped hand into the liquid for example, a large air pool will be held on the underside, not allowing the mold to ever touch the skin. When the cast is poured there will be a huge undefined blob where the air got stuck.

Dip & Dunk:

Human faces and ears are full of these concave areas. When you dunk your face down into the medium, pools will form in these areas. (see Chapter 5). The solution is to make sure these pools are filled with mold medium by either doing it before dipping or, in the FastMask™ technique use your hands to gently spread some into them as the model dunks their face in.

Engineering Air Paths:

Air Traps, you should recall from LifeCast™ Basics; Chapter 3, happen when some area of your mold turns up from some lower portion. Also remember that this phenomenon has nothing to do with the mold, it is strictly a casting event. Here are 2 more ways to prevent air traps. The first one below is excellent for controlling the exact positioning of your model. If made well a matrix such as this will be usefull for years.

Set Up: The first approach for precise control is to think upside down. This is the best approach when you want to adjust the exact position of the model(s). In this example I wanted this couple's fingers and hands to be identically positioned. Each above their part of the Yin Yang base to maintain the desired symmetry. This could only be done before the mold covered them up as follows:

Step 1: The mold making process is done by having your model's hand come up through a hole cut in the bottom of the matrix as shown. As you can see, this allows you to position things exactly as your design requires. The matrix has a sheet of plastic glued to the bottom with some extra allowed to extend through the hole. This excess is tightly held to the wrist by a rubber band to prevent the mold liquid from escaping.
• Notice the generous use of Velcro® type strips to prevent slip & slide as discussed above. Any parts of your design (in this case, the fingertips) which are at risk of air traps are attached through the bottom with common, 1/8" insulated wire.
• Pegboard is very convenient in this arrangement for reusable matrices. Simply plug up the holes you don't need. The model lightly rests the fingertips against the ends of these wires, providing what will become air paths in the next step.

Air Paths:

Step 2: This is where the upside down thinking pays off. When the mold has set, the model is released, the assembly is turned upside down and the wires removed for the pour.

Note: For additional support to prevent slip & slide, the mold should go all the way to the top edge of your matrix. When the assembly is turned over it all rests on the same level. Removing the wires creates thin tubes which now extend to the top surface from the fingertips.

When you pour your casting medium, the air escapes though these tubes. This allows the entire mold to be perfectly filled no matter how high or complex the air traps would otherwise have been.

This photo shows the results of just such a set up used to create the husband & wife's hands which were then mounted to an exotic wood base shaped in the Yin/Yang arrangement.

Engineering Air Paths:

The second approach should only be done when absolutely necessary for your design. Attach thin tubes such as cocktail straws or common, 1/8 inch insulated electrical wire to the area where a potential air trap will be formed, the fingertips in this illustration.

They must be firmly glued on with either spirit gum or some other adhesive that will keep them attached until the ArtForm™ mold sets.

Engineering Air Paths:

When the mold has set, remove the tubes first, then the hand which will come out easily since the suction will also be released by the tubes. When the ArtCast™ cement is poured, it will push the air (shown in blue) from the fingertips through the tubes and fill your mold.

BlendBag™ Liners:

The BlendBag™ is a unique tool for a unique medium. They also make excellent liners for a matrix that may not be waterproof. You can reuse them by just turning them inside out.

Put them inside the matrix pressed to the sides. Fill with water and insert the body part(s) you want to copy.

BlendBag™ Liners:

BlendBag™ Measurement:

1. Remove the bag and read the volume lines printed on the bag (see BlendBag™ Measurement in Chapter 2).
2. Add your ArtForm™ or Earthium™ powders and mix as described in LifeCast™ Basics.
3. Then simply slide the entire bag of fluid back into the matrix and do your LifeCast™!

Go To Chapter 2: Waste Not, Want Not:
Systems of Measurement & Conservation

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