OHMYGOSH, it's the second Tutorial Tuesday! I haven't quit yet! This tutorial was written up in response to a reader who asked about how I did the FX makeup on my Bioshock Splicer costume. I hope that other people will also find it a useful resource for working with gelatin for similar effects!
Take Note: this tutorial is not necessarily the "right way" to do things, nor the "best way", but is simply how I went about it when I made my own. Anyways, on to the project!
I made my initial mix of gelatin with 3 parts plain gelatin powder to 3 parts water to 1 part glycerin, though I might have changed the ratios a little between that test run and the final makeup, since I didn't take notes specifically regarding the mix. I know I made it on the runny side so it would smooth over the cotton balls easily. There are lots of recipes available online - basically you mix the ingredients and microwave it to get a smooth consistency and apply it while its warm (but not burning hot!!!)
And that's really all there is to it! By the end of the night of partying, the gelatin had dried and loosened enough that I was able to peel most of the appliances off whole (it can stick painfully to body hair though). Although they weren't good for re-use, it was nice that I didn't have to wait for the whole mass of gelatin to dissolve in the shower to get cleaned up. (Pictured below are each of the pieces after I peeled them off - upper arm, chest/neck, and various spits from my leg, on the front side and the back side).
If you haven't worked with plain powdered gelatin before, it smells awful. Kind of like wet dog. The smell fades as the gelatin cools and sets, but it never actually goes away. (good to be forewarned about if you're using it on your face). It's also very cool to the touch once set - downright cold even, which was something that really surprised me. But there's some good news - the squishiness of the cotton balls under the makeup is pretty fun. I was welcoming people to poke my arm all night and enjoying the "EWWW" reactions XD
Amaterasu (Imperial) 99%