Here is an easy inexpensive way to make plastic creations using just milk a microwave and white vinegar.
Step 1: What You'll Need
Milk, White Vinegar, and a microwave
Step 2: Milk
First microwave several cups of milk (I just used one) it depends on how much of the plastic you want to create so I suggest 1-3 cups of milk microwave it for 30-60sec for each cup of milk you have
Step 3: Adding the Vinegar
Next after your milk is at a moderately warm temperature you need to add your white vinegar again it depends on how much milk you are using I suggest you add 1 tablespoon of vinegar for each cup of milk you have. After adding the vinegar stir it into the milk for several seconds until there are several formed "curds". These "curds" form from a chemical in the white vinegar which I believe is called caresol that reacts with proteins in the milk.
Step 4: Straining
The next step is pretty straight forward just pour the clear and curdy substance from the bowl into a strainer and remove the curds from the strainer you will want the curds to be moderately dry to do the next step which is shaping the curds.
Step 5: Making Your Creation
Next what you will want to do is shape your creation I suggest using a mold so it stays in place (A cookie cutter will work however for this I just used a small cup). After you have the shape you want allow the substance to dry for 12-24 hours and it should be pretty strong.
Step 6: The Finished Product
After waiting a day or two the molded curds did dry and were very hard. However, as you can see in the pictures it broke up a little so I would suggest that you try to keep it as compact as possible. So this is a easy way to mold milk into plastic.
For more go to: http://adf.ly/MUTSW