This is quite an amazing little project that is really easy to do. You can make plastic with just milk and vinegar. I first ran across this process in a book about DaVinci. Evidently he had figured out a way to make this material and his recipe had been lost for a long time but recently rediscovered. At the bottom of this page I also have this tutorial in a video if you prefer to watch.

About making plastic from milk

It is a pretty interesting process in that there is a protein in milk called "Casein". This is a long string molecule that has very similar properties to plastics made from petroleum products. And it is very easy to separate this plastic out of the milk. If you are interested in a lot of amazing stuff from DaVinci himself you might want to check out the book:

Amazing Leonardo da Vinci Inventions You Can Build Yourself (Build It Yourself series)

The following picture is what I made with my plastic. They are a pair of dice for wargaming. All I had to do was make a mold out of some cereal box cardboard. Simple as that. I will show you how to do this.

The Materials You will Need:

About 1 cup of whole milk, better to use whole milk and not 2%. And a little over 8 oz works well, go with about 9 ounces if you can measure it. 4 Tablespoons of vinegar A microwave safe bowl Some kind of strainer A Microwave oven if you have one. If not you can just heat up the milk on the stove

Quick Overview: You warm up 9 ounces of milk in the microwave oven (or stove) without bringing it to a boil. Stir in four tablespoons of white vinegar. It will curdle. Pour it through a strainer or coffee filter. That is your plastic. Sit it on paper towels to let it dry out a bit and then you can shape it any way you like. Just let it dry under a lamp or on a radiator.

Step One: Put nine ounces of whole milk in a microwave safe bowl or container and microwave it for about two minutes. You just need to get it hot. Don't bring it to a boil! If you don't have a microwave then just warm it up on the stove.

Step Two: Stir in the four tablespoons of vinegar and it will immediately curdle. This curdling is the casein.

Step Three: Pour it through a strainer and let it sit a bit because it is so thick it will take a while to strain through.

Step Four: Scoop it into a bowl and work it with a spoon so it gets to be nice and smooth. Almost the consistency of Play Dough. You want to work out the lumps so you have a nice smooth plastic. This is easy to do and only takes a minute. I use the back side of a table spoon to really smooth it out by pressing it against the bowl.

Step Five: Scoop it onto some paper towels or coffee filters and let some of the moisture be pulled out. Half an hour or so would be good. Now let's make our dice.

I simply cut out two pieces of cereal box cardboard. Each piece is one inch by four inches. Then I fold and tape the pieces into a die shape. Now stuff it nice and tight with the plastic and you can set it under a lamp or on a radiator so it will dry. This will take at least a day to dry.

The Video Tutorial:

How to Make PlayDough
There are lots of recipes on how to make dough for kids to play with. This recipe is probably the best. Requires a bit of heating in a pan. Its a fun project in itself and the final product is fun too!

How to Make PlayDough

Make Your Own Playdough, Paint, and Other Craft Materials: Easy Recipes to Use with Young Children

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