A number of quick-drying whites are in demand by the carriage and car manufacturing trade, as well as in a few other industries. Foremost among these is flake white in japan. The term "in japan" is used, as a rule, to indicate its quick drying, merely as a short description. As japans are usually dark, mostly brown, it stands to reason that flake white, which is wanted for pure white jobs, cannot be ground in such a vehicle, hence color manufacturers will grind in a suitable vehicle of great paleness, generally a mixture of very pale hard gum varnish and turpentine, tempered with a small percentage of bleached linseed oil, according to the quickness of the varnish, which should be really in the nature of a rubbing varnish. The term flake white is often misconstrued, many in the trade believing it to be identical with zinc oxide, but it is not. Flake white is or should be same as Cremnitz white, a specially selected grade of lead carbonate deriving its name from the fact that, in the past, extra fine selections of white lead were sold in flakes, and when sold in cubes white lead was sold as Cremnitz white or Kremser white, deriving this name from the town of Krems, in Austria, where it was manufactured, pressed in cakes out of pulp lead and cut up into cube form, each of which was wrapped in blue paper separately and sold at a high price to artists that prepared their own colors in those days. Thus quick-drying white lead, whether it be furnished the consumer under the brand or trade name of "Flake White" or "Cremnitz White" or "Silver White in Japan," is a fine selection of dry lead carbonate, ground in medium soft paste form on a clean water-cooled stone mill, requiring about twelve pounds of the above-mentioned vehicle to eighty-eight pounds of pigment. Aside from being used under pale rubbing and finishing varnishes as a pure or a creamy white, it makes a very good base for very delicate tints on vehicle work of any kind where zinc white would not be elastic enough to stand the vibration incidental to vehicles or the exposure to the elements, and where lead in oil is too slow in drying for the rapid work demanded these days. It also serves very well as ground work for ornamental jobs where quick drying is required and where the finish is done with zinc white in a similar quick-drying vehicle. This is commonly known as zinc white in japan or in varnish, but its trade name is Chinese white in japan. Here the vehicle used in grinding should be still paler, and because of the tendency of zinc oxide to scale and crack it should also be tempered with more bleached oil, unless a longer varnish is selected. The zinc oxide for Chinese white is, or at least should be, the best grade of French process and free from moisture. Twenty to twenty-two parts by weight of the vehicle to seventy-eight or eighty parts by weight of the pigment will produce a paste of good consistency. The grinding must be done through a water-cooled stone mill that is very well cleaned and in a dust-free room. The mills with porcelain grinding disks that have been recommended for the purpose may serve well enough to grind artists' tube whites in a small way, but are more of a toy in a large establishment.
Knifing in lead, glazing lead or draw putty, as the material is known to the carriage trade, is often called for by exacting painters, and there are several ways to prepare this. For general use a good formula is to mix and grind on water-cooled stone mill of at least twenty inches diameter sixty parts by weight of dry white lead, thirty parts by weight of pure white lead in oil, six parts by weight of good twelve-hour rubbing varnish and four parts by weight of coach or gold size japan, adding during the grinding about two parts pure turpentine. The result should be 100 pounds of finished material. Or if the material is to set more quickly, eighty-eight parts by weight of dry white lead, mixed with six parts each rubbing varnish and coach-grinding japan, may be mixed and ground as above, adding whatever portion of turpentine may be required to make it pass freely through the mill. White rough stuff is prepared in a similar manner, with the exception that, instead of all white lead, whiting or a mixture of whiting and pumice stone is used as pigment. One of the formulas is as follows: - Fifty-four parts by weight of dry lead, twenty-seven parts English Cliffstone Paris white, six parts rubbing varnish, three parts pale gold size japan, ten parts turpentine. Another formula producing a less unctuous product, but one that will sandpaper or rub more freely, is made by mixing twenty-eight parts by weight of white lead, twenty-eight parts powdered soapstone, twenty-eight parts flour of pumice, seven parts rubbing varnish, seven parts turpentine and two parts pale gold size japan. This will, when reduced with turpentine to brushing consistency, make a very good filling.