This is a flexible sheet, potato starch+gelatin recipe that makes one 6 inch x 9 inch sheet (recipe can be scaled up – we’ve made 4 feet x 4 feet sheets with these ratios).
Materials:
—Shallow tray for drying (corrugated plastic works very well, which can be cut to desired size with 1 inch edges folded up to create a tray)
Method:
—60 ml water
—6 grams potato starch
—6 grams gelatin
—6 grams glycerin (3 grams makes a stiffer sheet)
Directions:
—Mix all ingredients well in a small pot
—Heat at medium, stirring continuously
—Continue stirring until mixture begins to turn whitish and thickens slightly
—Turn off stove
—Carefully pour the liquid out into your tray
—Quickly tilt tray to make sure the liquid reaches all 4 corners; place on heat-proof surface
Recipe Notes:
—Overheating or rapid stirring will cause bubbles to form that will impact your results
—Depending on temperature and humidity, bioplastic will take 4-7 days to cure before you peel it off the sheet. Don’t let it sit longer than a week before peeling it off the tray
—The sheet needs to be slightly rough to constrain the bioplastic – too smooth (don’t use glass or non-stick!) and the bioplastic will slip off of it and deform, too rough and it will be hard to remove
———This recipe can be used as a base to create composites: consider adding dyes, fibers, paper scraps, etc.
https://naturelab.risd.edu/discover/biomaterials-you-can-make-at-home
