XV. FUR DYEING: OXIDATION COLORS 155 The original patents. The first Oxidation fur dyes. Early difficulties. Solution of the difficulties. Progress with the Oxidation dyes. Para-phenylene-diamine: a typical Oxidation color. Range of shades obtainable. Mordants. Procedure in dyeing. Typical formulas. Combination of Oxidation colors with other dyes. XVI. FUR DYEING: COAL TAR DYES 171 Use of coal tar dyes. Basic colors. Acid colors; dyeing at higher temperatures. Chrome colors. Vat dyes. XVII. BLEACHING OF FURS 179 Purpose of bleaching. Steps in the bleaching process. Methods of bleaching. Bleaching materials with reducing action. Bleaching materials with oxidizing action. Blueing. BIBLIOGRAPHY 185 FUR DRESSING AND FUR DYEING CHAPTER I FURS AND THEIR CHARACTERISTICS Furs have in general two uses: as the goods which constitute the basis of the furrier’s art, and as the source of material for the hat manufacturer. In the latter case, only the hair part of the fur is utilized in the hat trade for the production of felt, the skin being either made into leather, or used as the raw material for making high-grade glue and gelatine. It is the furrier, therefore, who uses the great bulk of furs, and requires them to be dressed and dyed. In discussing the dressing and the dyeing of furs, there are, broadly speaking, two fundamental subjects to be considered: first, the raw materials employed, which are, of course, the skins or pelts as they come from the trapper. (Other substances used in fur dressing and dyeing are accessories, and will be studied in connection with the processes.) Second, all those operations, physical and chemical, manual and mechanical, to which the raw skins have to be subjected in order to obtain the finished fur, ready for use by the furrier.