View Full Version : Borax in casein

11-13-2006, 10:50 AM
Hi I was reading the facts page of the milkpaint.com company http://www.milkpaint.com/about_facts.html and noticed they mention that if milk paint has borax in it then it's not milk paint. I know the stuff you buy from sinopia.com and artstuf.com is a powder and you can add lime or borax. So why is it not considered milk paint with borax?

Does anyone know what the powder stuff you buy from companies is? Is it powder milk?



11-13-2006, 11:47 AM
Any paint made with milk is milk paint. :p Traditionally it is made with lime. Borax is another caustic alkali, like lime but more mild, that works as an emulsifier for the casein protein and water. Ash or ammonia also does this. Borax is a salt, and may crystalize over time, but is supposedly more durable than lime. Lime tends to make the paint more milky than borax. Ammonia carbonate is clearest but smells.

As I understand the casein powder processing, it comes from curdling milk with acids, and draining off the whey. Powdered milk is made by spray drying (whole or non-fat milk) and leaving condensed solids. Powdered milk may actually work for casein paint making, but may also contain additives I wouldn't need.