Here you can see the consistency of the casein glue. You can dilute it with any amount of water to make a thin wash, or use it full strength for a gesso, or add pigment to make a nice and hard milk paint. #DIYMilkPaint 🧵9/9 fin

Then you pour the borax water into the hydrated casein and watch for the chemical reaction to occur. Stop adding borax when the casein turns into a gooey glue roughly the consistency of syrup. The exact amount varies but roughly 1/3 borax water to casein. #DIYMilkPaint 🧵8/

The rehydrated casein needs to be activated by an alkaline chemical to become an adhesive for use as a paint binder. Any alkaline can be used. Borax is described as being good for making milk paint more waterproof, so I use borax dissolved in water. #DIYMilkPaint 🧵7/

Here's a picture of the amount of water that I prefer to leave on top of the rehydrated casein. You might want more or less, depending on the ultimate thickness of the milk paint medium that you desire. #DIYMilkPaint 🧵6/

After four hours let it sit still for about ten minutes. The rehydrated casein settles to the bottom and the excess water is on top. Pour off most of the excess water. Leaving perhaps 5mm of water on top of the hydrated casein. #DIYMilkPaint 🧵5/

Slowly sift the dried casein into the water, constantly stirring, taking about 60 seconds to avoid clumping. You likely will need to turn up the speed of the stirrer as it thickens. Let it spin for four hours to fully hydrate. #DIYMilkPaint 🧵4/

You need to rehydrate the dried casein with water, but the challenge is that casein really wants to form clumps. I've found that using a cheap magnetic stirrer to constantly keep it moving solves the clumping problem. Give it about 4 hours (or overnight) to get fully rehydrated. #DIYMilkPaint 🧵3/