Boiled Linseed Oil

Boiled linseed oil (BLO) is linseed oil (pressed from flax seed) treated with metallic drying agents so it cures in a reasonable timeframe -- hours to a day or two -- rather than the weeks true raw, untreated linseed oil takes to dry on its own. It's one of the most traditional and inexpensive penetrating oil finishes, wiped on, left to soak in, then wiped off, enhancing grain and color with a soft, low-luster sheen and offering modest but real protection.

The genuine safety note: linseed-oil-soaked rags generate heat as the oil cures through oxidation, and a balled-up pile of them can spontaneously combust -- a real, documented fire cause, not shop folklore. Used rags need to be laid flat to dry outdoors, submerged in water, or sealed in a metal container, never left balled up in a trash can.