CALICO-PRINTING 



659 



No. 224. Discharge Pink. (a) 2 gallons Brazil-wood liquor at 12 T., 4 oz. sul- 

 phato of copper, 4 oz. sal-ammoniac, 4lbs. starch ; boil, and add 8 oz. measure oxy- 

 muriate of tin at 120 T. : then take (b) 2 quarts of this standard, 1 quart muriate of 

 tin at 120 T. 



No. 225-. White Discharge. 2 gallons water, 8 Ibs. light British gum ; boil, and add 

 8 Ibs. tartaric acid, and 1 gallon muriate of tin at 120 T. 



Black Spirit black No. 210. 



After printing, hang for a few hours, and wince in a pit -with water freely flowing 

 into it ; then wince in chalky water, again in water, then wince in bichromate of potash 

 at 4 T., to raise the green and yellow ; wash and dry. 



The discharging agent in these colours is the protomuriate of tin, which, by its 

 superior attraction for oxygen, robs the peroxide of manganese of a portion. The 

 protoxide of manganese formed by this change being then soluble in the acid, and 

 subsequently washed away, the pigment Prussian blue and chromato of lead, also the 

 Brazil lake, are left fixed in the discharged place. 



PENCIL BLUE. Before the introduction of steam blues and the species of indigo blues 

 termed fast blues, the only blue that could be introduced into dyed prints was a solu- 

 tion of deoxidised indigo, dissolved in caustic alkali : this at first was applied by tho 

 printer with a small flat bit of 

 wood termed a pencil ; he dipped 

 this in the blue colour, and in- 

 stantly applied it to the proper 

 parts of the pattern, thus the 

 colour arrived at the cloth before 

 it had time to oxidise and the 

 indigo to become insoluble. It is 

 evident that this process was one 

 of extreme clumsiness, as it re- 

 quired skill to apply the blue just 

 to the proper places, and an ap- 

 paratus for applying the blue, 

 still called pencil blue, was at last 

 devised. It consists of a copper 

 case or box A, (fig. 390) in which is 

 laid a frame B, filled with pretty stout canvas. The box communicates by a tube with 

 the cistern c, mounted with a stopcock D. Fig. 391 represents the apparatus in 

 plan : A, the box ; B the canvas ; with its edges a a a a, fixed by pin-points to the 

 sides. The coloured is teered, or spread even, with a wooden scraper as broad as the 

 canvas. In working with this apparatus, the colour being contained in the vessel c 

 is drawn off into the case A, by opening the stopcock t>, till it rises to the level of the 

 canvas. The instant before the printer daubs the block upon the canvas, 

 the teerer, boy or girl, runs the scraper across it to renew its surface ; and the 

 printer immediately transfers the colour to the cloth. In this kind of printing great 

 skill is required to give even impressions. As the blue is usually applied to somewhat 

 large designs, it is very apt to run ; an inconvenience counteracted by dusting fine dry 

 sand upon the cloth as soon as it is blocked. The goods must bo washed within 24 

 hours after being printed. 



Pencil blue, before the introduction of China blues, was printed by cylinder with a 

 doctor-box. 



No. 226. Peticil Blue. 10 gallons of pulp of indigo, containing 40 Ibs. indigo, 40 Ibs. 

 yellow orpiment, 11| gallons of caustic soda at 70 T., 18^ gallons of water, 4 Ibs. 

 lime ; boil till quite yellow, when spread on glass ; let settle and thicken the clear with 

 120 Ibs. gum-Senegal. 



Pieces printed in pencil blue are washed in water immediately after drying and some- 

 times soaped a little. Mr. Bennett Woodcroft, struck with the waste of indigo attending 

 the printing of either China blue or pencil blue some few years ago invented and 

 patented a method of printing pencil blue by the cylinder machine. His plan was to 

 attach to an ordinary single-colour machine an India-rtibbor apparatus which enve- 

 loped the colour-box and piece after printing: this apparatus was filled with coal-gas ; 

 a glass plate formed part of the long bag through which the piece travelled after printing, 

 so as to enable the printer to see the progress of his work. By this means the de- 

 oxidised iiidigo was fairly applied to the cloth, and oxidation only ensued when the 

 piece left the apparatus. Tne saving of indigo was said to be considerable, but the- 

 plan was not generally adopted. 



Pencil blue is sometimes printed along with garancin mordants and dyed garancin. 

 Tho blue withstands the dyeing and clearing. In America it is often thus printed. 



SAFFLOWER DYEING. The beautiful but fugitive colouring matter of safflowcr in 



TJTJ2 



