636 CALICO-PRmTING 



with soap and boiled for an hour, taken out, washed well, and put in a strong pan charged 

 with soap and water, the lid screwed down, and boiled at a pressure of two atmospheres, 

 either by direct fire or high-pressure steam, for two or three hours, then taken out, 

 washed, and put in a bock with water at 160 F. charged with a little hypochlorito of 

 soda ; they stay in this about ten minutes, and are then washed and dried. In some 

 print-works, after the high-pressure boil, the pieces are spread out on the grass for a 

 night or two, and then cleared in hypochlorito, &c. The use of the acid here is not 

 very clear, it probably completely purifies the colour from iron which may have been 

 in the mordant, but it also seems to render the combination of alumina, tin, lime, 

 colouring matter and fat-acid a definite one by removing a small quantity of the mor- 

 dant. The French chemists assert, that after the final process, a definite atomic com- 

 pound of lime and alumina, colouring matter, and fat-acid remains. 



The quality of the soap used by printers is of great importance. It is made for them 

 specially from palm-oil, and requires to be as neutral an oleo-stearate as possible ; an 

 alkaline soap like domestic soap would impoverish and degrade the shades. 



The soaping process has a two-fold action : 



To clear the white while decomposing the compound of lime and colouring matter 

 which forms the stain ; this is done by double decomposition, forming oleo-stearate of 

 lime, which dissolves or forms an emulsion with the excess of soap ; and a compound 

 of soda and colouring matter, which dissolves. In its action on the dyed parts, it 

 probably first removes resinous and other impurities which are loosely held by the 

 mordant, and secondly gives up a portion of its fat-acid to the dyed parts the 

 resinous acids or possibly phosphoric acid from the dyed parte, by combining with the 

 soda, setting free fat-acid for this purpose. 



In reference to the above Swiss pink style, it may be observed that various shades 

 of pinks are required for different markets, and where as in many cases a full rich 

 inexpensive colour is required, the method of dyeing at low heats as described above 

 is unnecessary, and the becks are brought nearly to a boil. Where an orange-tinted 

 shade is required the goods may be dyed with garancin of good quality or with a 

 mixture of madder and garancin. 



. A few years ago Mr. Thomas Lightfoot, of Accrington, discovered that madder or 

 garancin-dyed goods, if dried and steamed in the manner usual in fixing steam 

 colours, became much less degraded by soap in the clearing process for Swiss pinks, 

 and that a considerable saving of madder or garancin might thus be effected, weaker 

 mordants and consequently less dye-stuff being employed. Mr. Lightfoot patented the 

 use of steam as an intermediate process between the dyeing and soaping of these 

 colours, and the process is now generally used. Mr. John Graham had in 1855 

 patented the use of steam for ' fixing ' the colours of dyed cloth, but his patent does 

 not mention any subsequent process, and it is doubtful in what respects his so-called 

 fixed colours were better than the ordinary dyed goods. Some printers pass the dyed 

 goods through an oily emulsion previously to drying before steaming, with the object of 

 causing a combination between the base of the mordant, the colouring matter ajid 

 the oily acid, and so dispense with some of the usual ,oaping processes. Swiss pinks 

 are sometimes ' covered ' with a pattern which harmonises with that of the pinks, in a 

 discharge yellow made of salts of lead mixed with acid ; and after ' covering/ the goods 

 are passed through strong chloride-of-lime solution which, being decomposed by the 

 acid, the free chloride liberated destroys the pink-dyed part under the yellow, and the 

 insoluble lead salt left in its place is dyed or raised with bichromate of potash. A 

 style of madder work occasionally extensively printed is the madder orange style, 

 where the orange is a salt of lead and called ' madder orange ' because it has passed 

 through the madder process along with the proper madder colours. The cloth is 

 padded with solution of sulphate of soda containing 4 ounces of the crystallised salt 

 per gallon, dried and printed in madder black, and purple, or black, red and purple 

 with orange, say of Nos. 4, 6, 27, the orange No. 64a, and cover, or cover and pad 

 with weaker purples, an acid 33 to 35 may also bo printed along with the other 

 colours. After ' ageing,' instead of dunging, run through a cistern set with 2 Ibs. 

 crystallised sulphate of soda and ounce of crystallised phosphate of soda per gallon 

 of water at 150 F. ; wash well and dye with madder as usual ; wash and clear by 

 running through a beck set with 300 gallons water at 140 F., 2 quarts chloride of 

 lime solution at 8 Twaddell, and 2 quarts of solution of carbonate of soda at 8 

 Twaddell, run through water, then through the spiral soaping becks at boil for half 

 an hour, then run through water, next through a chloride of lime and soda cistern 

 Bet as before but boiling, then through the spiral soaping becks at boil, again into 

 chloride of lime and soda set as above but at boil ; wash well and raise the lead 

 colour to yellow by passing for half a minute through a cistern containing 300 gallons 

 of cold water, 30 Ibs. of bichromate of potash and 3 quarts of sulphuric acid ; run 

 from this into water and wash well; to change the yellow into orange run through 



