CALICO-PRINTING 



609 



machine, as it is easily washed by being passed through . a special washing 

 machine, which will be found described subsequently. An India-rubber blanket 

 will print 20,000 pieces, which is twice as much, as a woollen one will do, the 

 price per yard being also lower. Several descriptions of these blankets are 

 made by Messrs. Macintosh, some of them having a coating of vulcanised India- 

 rubber on the face that is printed from, thereby giving a still more elastic 

 surface. A great improvement has been recently made in these India-rubber 

 blankets by shrinking or preparing the cotton previous to cementing, according to the 

 patent process of Mr. John Mercer, viz. by soaking in strong alkali, and afterwards 

 in dilute sulphuric acid; this process contracts the fibre to a certain extent, Jind the 

 cloth is found to possess a great increase of strength. When made into blankets they 

 are found to be more capable of resisting the severe strains of the printing process, 

 and consequently many more pieces can be printed from them than from the old sort. 

 They are made by Kay and Co. of Accrington, and others, and are now in general use. 

 The woollen blanket, however, seems to be preferred for several styles. Several 

 patents have been taken out for printing without blankets, but have never come into 

 general use ; but recently a mode of printing with grey or unbleached calico has come 

 into use, which is very favourably spoken of. In this method a roll of grey cloth is 

 BO disposed behind the machine that the fabric can be conducted five times through 

 the machine before finally going away to be wound on a beam for removal. There 

 are, therefore, five layers of cloth under the white calico when printing, which gives 

 a sufficiently elastic bed for printing from; and very delicate shapes can be got. 

 Any given part of the grey cloth is five times uppermost on the pressure cylinder, and 

 consequently one piece of grey cloth is used to print five pieces of white. Gutta- 

 percha pressure cylinders, or ' bowls,' have been suggested by Dalton, an English 

 printer; but though theoretically preferable to iron, they do not appear to be much 

 used. 



In printing with aniline black (No. 240), the grey intermediate cloth, unless 

 removed from the machine without drying in the hot room,' and before this peculiar 



black has begun to form upon the cloth, will be stained and spoiled for future printing 

 upon, in consequence of the extraordinary fastness of this colour, which, resists the 

 ordinary bleaching operations ; and this is the place to describe a very simple 

 arrangement for wetting the grey pieces, after they have served their purpose, and 

 thus preventing the formation of the black. The arrangement (/a. 354) i a that in use 

 at the Oriental Print Works at Apponaug, in the United States. A /ia the printinc- 

 VOL. I. R B 



