Hmm... looking in various places on google's first couple of pages for "mix oil paints," linseed or safflower oil, powdered pigments, a small quantity of beeswax, and (historically) white lead for brightness are the only things I see mentioned, along with warnings that water soluble paints are not compatible with oils and at best will lead to streaks and bubbles rather than a smooth color. So, it looks like $creator was telling a good story without letting pesky reality interfere. Because magic!
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows