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Whipped dog! He has exactly what you are looking for and he uses kremer pigments which are very pure. A .3 CrOx and a .1 FeOx. Excellent value too. I think around $3 and you get enough for two life...

I used to mix with a 50/50 solution of mineral oil/rubbing alcohol. The mineral oil helps to keep the CrOx on the wood after drying and the alcohol thins it out so you can spread it more evenly....