Paint has an ancient history and a long relationship with milling, whether that’s the paint on the mill, paintings of mills or paint-making mills.
Paint is made up of three main components, the pigment, binder and the solvent. The pigment provides the colour of the paint and can be made out of many different materials. Today usually this is chemically produced such as white produced using titanium oxide, or iron oxide which is used to produce yellows, reds, browns and oranges. Previously, however, all sorts of natural materials and minerals have been used such as azurite which made a blue pigment and was used throughout the Middle Ages and Renaissance. Pigments come in the form of solid powders so need a material to stick them together, this is where the binder comes in. Again this is now often chemically produced however egg yolk used to be used. The problem with binders is that when mixed with pigments it produces a thick gloopy substance that would be impossible to use. A solvent is added to the mix to thin this down.
Painting has a long and diverse history as both a means of decoration and to provide a protective layer on materials. The earliest example of paint comes from prehistoric cave painting. However it was in Ancient Egypt and Classical Greece and Rome more methodical production was introduced. For example white was produced by mixing lead with vinegar in pots and then covering the pots in manure, whilst sand, lime and copper were mixed and heated to create Egyptian Blue. It was in the Early Medieval period that the value of paint increased rapidly. Lapis Lazuli, for instance, was mined from Afghanistan and create an incredibly rich blue. It was hugely expensive, costing as much as gold leaf and so was only used for images of great importance, for instance, depictions of Mary in bibles and Psalters.
From the 16th through to the 19th Centuries paint continued to develop with the invention of oil paints allowing new styles of paintings on far larger canvases as well as advances in colour brought on by discoveries in the new world and chemistry. The technological and scientific revolutions in the 19th Century would open up painting to a far larger audience, with mass chemical methods making it cheaper and easier to produce paint. Most artists also stopped mixing their own paints and instead used the services of colour meant who made readymade mixes. Yet all this would bring an end to traditional paint milling, and by 1940 acrylic paint was introduced.