This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Japanning. The art of coating surfaces of metal, wood, etc., with japan or varnish to produce a high black luster. Japanning liquid is made by cooking gum shellac with linseed oil in a varnish kettle. The articles to be coated, such as hair pins, pants buckles, buttons, etc., are immersed in the liquid and then dried and hardened by means of a high temperature in stoves or hot chambers.