I wanted to explore bioplastics that stick onto the skin with edible materials. Some people call it hydrogel, and some call it bioplastic. Below are 3 videos I referenced before making this tutorial. The first one added a lot of glycerin because she wanted to stick it onto a window, and the second one wanted to make thin plastic films for food packaging. I had to experiment the thickness and ingredient proportions to get it to stick to the skin.

Glycerin x Agar bioplastic window sticky tutorial

Bioplastics: Edible food packaging film

DIY Hydrogels (She also added tea!)

Step 1: What You Will Need

Gelatin

https://www.target.com/p/knox-original-unflavored-... <<< I bought this one from Wholefoods

https://www.amazon.com/gp/product/B000MGR302/ref=p...

Glycerin

https://www.amazon.com/gp/product/B00IK4J5YA/ref=p...

Measuring cup

Measuring spoon

Small pot

Mold (I used a ceramic plate)

Step 2: Choose Your Proportions

What I've tried:

Hard Plastic (left):

Water 1 cup

Gelatin 1 tablespoon

Glycerin 1/2 tablespoon

Dry Time: 15 minutes

Soft & Tough Plastic (center):

Water 1/2 cup

Gelatin 1/2 tablespoon

Glycerin 2 tablespoon

Dry Time: 15 minutes

Very Soft & Sticky Plastic (right):

Water 1/2 cup

Gelatin 1/2 tablespoon

Glycerin 4 tablespoon

Dry Time: 3 hours

Made Feb 11th & Still Waiting to Dry...I want this to be super sticky

Water 1/2 cup

Gelatin 1/2 tablespoon

Glycerin 2 tablespoon

Dry Time: ? hours

Step 3: Mix Water & Hydrogel

Do not heat the water yet. The dude my reference video did it because he was proud of how chefs heat water in kettles for efficiency, and I have no problem with that. However, throwing gelatin powder into hot water will cause it powder to clump. This other video shows a lady dissolving gelatin in cold water first. I tried and it dissolved beautifully. There will still be minute clumps, but it will all dissolve after you start heating up.

Step 4: Heat Up & Add Glycerin

Heat up the pot, but do not scorch the gelatin with high heat. Otherwise, you will successfully create the smell of a dead cow. Stir until the gelatin is dissolved, this should happen pretty fast. It's ok to have a little bit of burnt and dried gelatin on the side of the pot. Then, add the glycerin in and stir a little bit more.

Step 5: Pour Liquid Into Mold

I guided the liquid with my chopsticks so it doesn't drip all over the edge of the pot. Also, I had to make sure the surface is flat, so I added some coins to the bottom of the plate to adjust that. Note that if you use a lot of glycerin, like my third recipe, making it too thick isn't a good idea. It breaks apart too easily.

Step 6: Wait to Dry & Remove From Mold

Dry time:

Again, the dry time of my 3 recipes range from 15 minutes to hours. More glycerin takes longer time to dry. Eventually though, after 9 days, the one with the most glycerin curled up the least and maintained most flexibility.

Peeling strategies:

If your cast is thick, try dragging the edge of the plastic towards the center to loosen it up. Do this all around the plastic if you want to be safe. If it's very thin, you have to be very careful with this step. Sit down, take a deep breath and do this slowly...