Plaited silk fishing lines are waterproofed by soaking in equal parts of boiled linseed oil and copal varnish, then stretching in some convenient position to dry, at the same time wiping off superfluous dressing with a rag. Drying will take a considerable time; to accelerate it, 1 part of gold size may be used instead of \he varnish to 2 parts of boiled oil.