Pigment Use in Oil Painting

However, when the water dries, then we are looking at a refractive index difference of 0.33 between that of air (1.00) and calcium carbonate. This explains why whitewash is so effective. 

One of the more durable drying oils that has been in use for centuries is linseed oil, pressed out of the seeds of the flax plant—a scarce commodity until the linen industry expanded and thus made more flax available for other purposes as well. Hardening of the soft linseed oil films by rosin and adding turpentine created an enhanced varnish for wooden floors, fine furniture and for Stradivarius violins. 

There are other factors that need to be considered to make up a good paint, including pigment particle size, solubility of the pigment in the medium, media adsorption, reactivity with the medium, etc. There is so much more to color than meets the eye  

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