Boiled linseed oil mixed with iron oxide is a classic recipe for "oilcloth". It was a staple for water resistant outerware for ages. I remember being told once why they added the iron oxide, but for the life of me I cannot remember why. Just remember that once you have treated canvas with any of these conpounds, beeswax, turpentine, oil, whatever, you have added an accelerant to a flammable material.
Many an oilcloth shelter has gone up like flashpaper in a furnace when a candle strayed too close! It's the reason why many rendezvous specifically require WHITE CANVAS ONLY in camp. Yes, oilcloth was very traditional and period correct...so is dying tragically early in a horrible fire.