FINISHING PROCESSES 51 



which has been completely dried out. There are also 

 " samming machines," which by means of rollers squeeze 

 out the excess liquor. Sole leather is dried out and finished 

 immediately after tanning, but dressing leather is often 

 " rough dried " out of tan liquors and wet back for finishing 

 when required. Dressing leather is often treated in different 

 factories ; tanners selling it as rough leather and " curriers " 

 finishing it. 



Scouring is one of the first operations in finishing leather. 

 The grain side is wet and worked with brushes and stones 

 until the bloom and loose tannin are removed. This pro- 

 cess aims at producing a good even colour and level surface, 

 but is liable to cause a loss of weight. Dressing leather is 

 often scoured on both grain and flesh, and weak soap or 

 borax solutions are used to assist the process. In this opera- 

 tion hand labour has been now quite superseded by machine 

 work. A great variety of machines have been devised. 

 The mechanical working of leather takes place in various 

 parts of finishing. These operations, known as " striking," 

 " setting," " pinning," " jacking," may be carried out often 

 by the same machine as used for scouring, but with a change 

 of tool. The object of these operations is to get rid of 

 wrinkles and creases, to produce softness, pliability and area, 

 and to remove superfluous moisture, grease, dirt. The tools 

 are of steel, brass, slate or vulcanite. Scouring is often 

 effected by putting the goods into rotating drums together 

 with extract and sumach. The bloom is removed by 

 friction, the colour is improved by the sumach, whilst the 

 extract keeps up the weight. 



In finishing sole leather firmness is enhanced by " rolling." 

 A brass roller passes to and fro over the goods with the 



- ion of considerable pressure. The operation is 

 out by machinery. 



in important operation in the case of many 

 A hers. Its object is to produce a uniform 



kness of the leather and an even surface on the floh 

 side. The sammed goods are laid over suitable beams 

 and shaved with special sharp knives which possess a turned 



