JAPANNING. 253 



low, or Dutch pink, or the orange lake, which will 

 make a brighter orange ground than can be pro- 

 duced by any mixture. 



Purple Japan Grounds. 



These may be produced by the mixture of lake 

 and Prussian blue ; or of a darker kind, by Vermil- 

 lion and Prussian blue. They may be treated as 

 the rest, with respect to the varnish. 



Black Japan Growids. 



Black grounds may be formed without heat, by 

 either ivory black or lamp black ; but the former is 

 preferable where it is perfectly good. These may 

 always be laid on v;ith shell-lac varnish; and have 

 their upper, or polishing coats of common seed- 

 lac varnish, as the tinge or foulness of the varnish 

 can here be no injury. 



Common black Japan grounds on iron or copper, 

 produced by means of heat, are formed thus : the 

 piece of work to be japanned must be painted over 

 with drying oil, and a little lamp black ; and when 

 it is of a moderate dryness, must be exposed to 

 such a degree of heat, as will change the oil to 

 black, without burning so as to destroy or weaken 

 its tenacity. The stove should not be too hot 

 when tire work is put into it, nor the heat increased 

 too fast, either of which errors would make it 

 blister ; but the slower the heat is augmented, and 

 the longer it is continued, provided it be restrained 

 within the due degree, the harder will be the coat 

 of japan. This kind of varnish requires no polish, 

 having received, when properly managed, a suffi- 

 cient one from the heat. 



