Linseed oil is an amber colored oil extracted from linseed, the seed of the flax plant. The oil obtained from hydraulically pressed seeds is pale in color and practically odorless and tasteless. Oil that has been boiled or extracted by application of heat and pressure is darker, with a bitter taste and unpleasant odor. Linseed oil is used as a drying oil in paints and varnishes and in making linoleum, oilcloth, and certain inks.
Flax seed yields from 30 to 40 percent linseed oil by weight. The linseed meal, which remains after the oil has been pressed, contains 30 to 40 percent crude protein and is a valuable feed for livestock.
There is a chemical called cyclopentadiene which, when it reacts with linseed oil, makes the linseed oil dry more quickly on contact with oxygen.