EUREKA! A Non-Toxic Cold BioPolymer Puppet Casting Formula
It took me a full two weeks of researching adjacent formulas online, ordering a long list of materials, and experimenting with formulations from scratch until they began to take shape in my mind.
It's basically a stabilized gelatine like those that make-up artists typically use to fabricate facial appliances for special effects. The difference here is that I've added ingredients and techniques to strengthen the mixture so it should stand up to endless flexing at joints during animation. So far so great.
I developed this formula the same way that I cook, intuitively, ridiculously, frugally, and with zero clue how professionals would go about it, often with delicious results.
I knew that I didn't want to use toxic materials because I work comfortably in my home and do what I can to protect my health as much as possible.
Have used proper casting materials like latex and silicone in the past but would prefer to not buy them, use them, or dispose of these materials going forward.
I didn't want to set up an oven to bake the molds, not even to bake off the Cosclay samples I made. Too much energy/natural gas to heat a whole oven for samples. Heating like that doesn't fit with my preferred workflow.
Had intended to use silicone caulk for this but found the VOCs to be too toxic for me to get involved with. Opted for this food-grade approach as it seems to work better for me.
The texture of this Non-Toxic Cold BioPolymer formula is perfect so far after a week or two. It's incredibly flesh-like, fully flexible without cracking, similar to silicone. Firm, easy to work with. And zero waste. It's reusable too!
Use mixture warmed/chill to set
Heating evaporates water and water molecules in glycerine, leaving stabilized polymers behind.
Add powdered 300ยบ Bloom strength beef gelatin* (GEL) in small dustings over the water slowly to insure full whetting. Gelatin contains long-chain amino acids that tightens when cooled and stretches when warmed. Gelatinous and smooth like custard when ready to use. (*there are vegan alternatives to this but fyi agar agar won't work.)
Hydrogen molecules in the gelatin bond with water molecules in the mixture, leaving the proteins to bond with themselves. Once water is evaporated, the mixture becomes hardened.
Warm mixture slightly--never boil--to ensure collagen fibers remain long (excessive heat loosens their molecular bonds)
Heat to liquify on a mug warmer (HEAT SOURCE) (maximum heat approximately 180ยบF) (*Most people opt to use microwave ovens to heat the gelatin (in small increments to avoid boiling) but I avoid microwaves as well, never had one and won't use them.) A double boiler could be used on low heat over heated water to make larger batches. For the development and tests the mug warmer was convenient on the work table and what's even better, the mixture can be reused and reheated over and over! In fact, it gets stronger as you do. Mistakes? No problem! Cut it up into small chunks and warm it again and again!
I use small second-hand clear glass pyrex custard cups on the mug warmer to heat the mixtures.
(Use nothing with protease enzymes (like pineapple or vinegar) as they will break the chemical bonds in the gelatin's proteins.)
Add an amount of liquid glycerine (ELASTISER) to the dissolved gelatin and water mixture to further dilute and stabilize.
Add your colorant of choice to this dissolved gelatin in water mixture stage. I used custom-mixed food color drops.
Use a portion of PVA (Elmers Glue All) to elasticize the formula
A small amount of Cornstarch kicks the mixture (CATALYST and strengthener).
Adding powdered or liquid Sorbital is said to aid in cast's preservation (TBD). (PRESERVATIVE)
Use two drops of honey in 83ยบF water before adding high power rapid-rise yeast (FOAMING) for best active foaming.
Allow foam to activate for several minutes until frothy.
No Vasoline, or any other mold release will be needed when using Ultracal molds. The mixture comes away from everything, even fabric. It's sticky, like rubber cement when soft, but doesn't actually adhere to anything except itself once set.
Brush thin warmed liquid skin coat into both sides of the mold and coat the armature, before filling further, to avoid air bubbles/pockets.
Backfill the mold with warm mixture with the armature in place.
Laminate a layer of washi (Tengucho/Mulberry pulp paper, which is transparent yet strong when whetted). over both mold halves with liquid mixture to support the sculpture's structure. (MEMBRANE)
Close the filled mold, strap it tight, and put it in the fridge or freezer to set it up firmly quickly.
Armature has to be made as slim as possible to ensure the mixture surrounds it on all sides of the mold.
Pop completed casting out of the mold when the gel is firm.
Allow casting to air cure over several hours, then carefully trim excess from seams.
Cover casting with washi mรขchรฉ technique using flexible medium (matte medium or fray-stop glue) to unify casting skin surfaces and allow for finishing with color/shading of your choice. (ENCAPSULATION)
Finished casting can be trimmed where too thick, and adjusted to perfect the form with wood glue/thick glaze.
Interesting that actual animal collagen is being used as puppet's own "collagen" tissue.
And that washi (tengucho/mulberry) is used as puppet "fascia" tissue similar to how human bodies are constructed.
These puppets cannot be allowed to come into contact with moisture or excessive heat theoretically.
The long-term storage of these puppets is unknown. No idea yet whether moisture from air, mold growth, vermin, or dramatic shrinkage over time will affect them as this is a new formula. They smell faintly yeasty due to the yeast.
No mask or gloves are required unless adding zinc oxide to the mixture while heating, use recipe at your own risk, as always.
No waste, mixture can be reused repeatedly (gets tougher each round of heating and cooling and reheating).
No noticeable fumes/VOC (always use at individual risk).
All ingredients are food grade. (Again, use at own risk).
Materials are easy to acquire and relatively inexpensive.
Nothing in it contaminates the environment, even in landfill, with the only exception being minute amounts of matte medium or acrylic paints, if any are used on the finished puppets.
Additional Additives:
Small amounts of finely grated wax crayon for colorant or plain beeswax for greater stabilization.
Zinc oxide makes the casting more resistant to tearing (Use caution as it's hard to ensure this material doesn't contain lead).
Sorbital is said to aid in preservation, TBD.
Water smoothes the surface of the gel mixture when first applied warm and still in soft gel form.
Please visit again for further exciting posts. Planning to share the results for Halfland's new 2023 puppet fabrication. The executive production department (still also me) will determine how much effort can be put into each character or if a simpler solution needs to be decided. Thanks, all!
Thanks for passing on your hard won knowledge.
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