Step 1: Preparing the Milk/cheese

Add milk and vinegar to a saucepan, lightly mixing (but not more) the mix.
Turn on the heat to a low setting, you dont’ want it above 46c or “until just a wisp of steam”
Wait for ~5-10mins for the whey and the curds to separate. The whey around the edges should start going pretty clear
Transfer the curds into a colander lined with doubled over cheesecloth.

Rinse the curds several times – you want any remaining vinegar to be cleaned off so it doesn't react later on.

Watch as your paint recipe disappears as your wife realises you’ve just made cheese

You can leave it at this stage in the fridge for awhile/until you're ready to make up the rest of the paint.

Step 2: Making the Paint

Measure out and mix the lime and water in a separate container. Wear gloves for this part, hydrated lime isn't the greatest for you.

It doesn’t take too long for it to become a smooth paste.
Add the curds into the lime paste, mix like crazy.
For the smoothest paint possible strain through a stocking. Skip this step if you want it lumpy.
In a separate container, mix up the oxide powder and water until its ‘all wetted’.
Combine the wet oxide powder into the curd+lime mix, mix until smooth
For the smoothest paint possible strain (again!) through a stocking. The oxide powder may have introduced new lumps

Done. Paint stuff. I used a synthetic bristle brush, washes out super easy.

Step 3: Bonus Round

You can also add a small amount of borax for antimicrobial properties.

You can use other things to add pigment, like universal tints, acrylic paints, probably food dye

We’re still experimenting with what works for us and is cheap.

If its going to be on a surface thats wiped down or exposed to moisture, I’d highly recommend applying a clear topcoat - any polyurethane would work, but sticking to a water based/acrylic coating will also dry fast and be lower in VoC's.