I'm just going to use this blog as for general ideas and notes. Later I will design and improve the overall Blog. I'm not a great writer an don't intend this to be anything but a notepad.
I was reading an interesting article on ancient Indian cave paintings here: http://www.shumla.org/discover/paintmaking.htm . The archaeologists were attempting to manufacture the paint they used, but they would need to use the ingredients that would be available to the Indians at that time. Ruffly 2000 years BC.
They know through tests on samples what pigments were used, but they didn't know for sure what the binder was. It would have to be something that lasts 4000 years and be easily available in the area. Animal fat is a common binder is often used by native tribes. After trying other possibilities they decided that animal fat was the most likely binder.
But what did they use as a thinner? They hypothesised that a thinner must have been used to make some of the cave paintings. There was no petroleum solvents or turpentine available. Water can't thin paint with animal fat (oil) as it's binder. They eventually tried adding an extract of Yucca root (a natural soap) to the water and it worked beautifully as a thinner for the fat based paint. It apparently even added some very nice handling properties to the paint.
I'm would think that this should work just as well with linseed, or other oil based paints too.
This predates the invention of water mixable oil paints by nearly 4000 years.
I'm going to try adding a little concentrated Yucca extract to linseed oil and see if I can use it to make a water soluble oil based paint. If this is indeed what the Indians used then it should be a very tough and permanent paint, as it lasted 4000 years on the cave walls!