Gelatin Bioplastic

What It Is

Gelatin is a biopolymer made from protein polymer chains of amino acid monomers, derived from the collagen in pig skin, cow bones, or fish scales. When dissolved in warm water and allowed to cool, it forms a gel. Mixed with glycerin as a plasticizer, it dries into a translucent, flexible bioplastic sheet.

Compared to agar, gelatin produces a warmer, slightly amber-toned material with less shrinkage. It dissolves more readily in warm water — which makes it unsuitable for some applications (cyanotype on glass) but highly workable for casting and embedding.

Why Artists Use It

Gelatin bioplastic has a bodily quality that agar lacks — it comes from skin and bone. For artists exploring themes of memory, impermanence, and the organic body, this material history is meaningful. It also embeds inclusions more easily than agar, as it sets more slowly and remains workable at lower temperatures.

Gelatin is sensitive to humidity and temperature — it softens in warm weather and can grow mould in humid conditions. This responsiveness is both a limitation and an artistic quality.

Historical Context

Gelatin has been used in photography since the 1870s, when Richard Maddox developed the gelatin dry plate — replacing the wet collodion process and making photography widely accessible. Gelatin silver paper remained the dominant photographic medium for over a century. In biomaterial practice, gelatin became a standard biopolymer for flexible, transparent sheets alongside agar and alginate.

Basic Recipe

From Jay Lee's bioplastic workshop (adapted from Margaret Dunne's Bioplastic Cook Book):

	Brittle			Flexible
Glycerin (g)	0.0	1.8	3.6	7.2
Water (ml)	60	60	60	60
Gelatin (g)	12	12	12	12

1. Add gelatin, water, and glycerin into a pot.
2. Cook over medium heat — do not boil. Stir until the gelatin is fully dissolved and the solution starts to thicken.
3. Remove froth with a spoon for a smooth, glossy surface.
4. Tape a wooden frame onto a non-stick surface and pour in the solution.
5. After 24 hours, remove the frame and hang-dry.

Note: Gelatin is not suitable for cyanotype glass plate coating — its sensitivity to humidity and acidity interferes with the iron chemistry. Use agar instead (see: Cyanotype on Glass).

Tools & Safety

Same tools as agar bioplastic: kitchen scale, saucepan, spatula, frame, non-stick surface, antibacterial spray. Gelatin is food-safe. Avoid boiling — high heat can denature the proteins and weaken the final material.

Common Failures

• Boiling: Destroys protein structure, weakens the sheet. Keep temperature below 80°C.
• Mould in humidity: Gelatin is more susceptible to mould than agar in humid climates. Dry thoroughly and store in dry conditions. Sterilize all embedded additives.
• Melting in warm weather: Gelatin softens above ~30°C. Store in cool environments, especially in summer.
• Froth: Stir gently and skim before pouring.

Archival Notes

Gelatin bioplastic is not intended for permanent archival use — it will soften in heat and degrade in humidity. Store flat in acid-free tissue in a cool, dry space. Avoid temperatures above 25°C and humidity above 45%.

Jay's Studio Note

Gelatin and agar often work as partners in bioplastic research — agar for photographic applications, gelatin for embedding work where a warmer, more forgiving surface is needed. In experiments mixing gelatin with coffee grounds and egg shells, the resulting composite feels more like a found object than a manufactured one.

Related Materials

Agar Bioplastic — plant-based alternative, less prone to mould · Botanical Embedding — technique for embedding in bioplastic · Animal Glue (Hide Glue) — related protein-based binder, traditional use