PRINTING ON CALICO. 



the wafti-wheel. The calicoes are then to be regularly and 

 thoroughly dried, which llnifhes thefe prehmn.ary opera- 

 tions, known in the trade by the term preparation; fo that 

 thofe cloths which have paflid through thefe mampulations 

 are faid to have undergone a preparation. Befides the uies 

 already mentioned, there .s another advantage attending 

 thefe procefTes, -vl^. that the cloth which has ""dergone this 

 preparation will bleach fooner, the co ours wd be brighter, 

 and the whites more delicate, than they would have been 

 had they not gone through thefe previous operations. 



The next procefs is that of calendering. Here the goods 

 are paffed through a fet of rollers, which gives them a glofs, 

 and the appearance of their having been ironed. They are 

 now fit for printing. For copper-plate printing, or cylinder 

 work, the procefs of calendering is omitted. 



In printing fail colours, the artift ufually proceeds in this 

 ,vay: he lavs the piece of calico, which has been already 

 fmoothed by calendering, upon a ftrong thick table, which 

 is previoufly covered with a woollen cloth. He then pro- 

 ceeds to apply one or more mordants, as the cafe may 

 require, for fixing the intended colours. Thefe mordants 

 are applied by means of wooden blocks, with the patterns 

 formed upon them. Thefe blocks were formerly chofen of 

 holly, and the cutting them was a feparate branch of the 

 bufinefs, and was called block-cutting. Of late years, how- 

 ever, a conliderable improvement has been made in this part 

 of the bufinefs by the introduction of brafs or copper ; that 

 is, the pattern, inftead of being aftually cut in the wood, 

 is now formed by means of flender pieces of one of thofe 

 metals being firmly fixed to the block, fo as to produce the 

 pattern intended. This alteration was occafioned by the 

 perifhable nature of wood, on account of which every 

 printer incurred great and unneceflary expence. The pat- 

 tern when thus formed with copper, is not only more lail- 

 ing, but it has alfo the advantage of giving greater fharpnefs 

 and beauty to the impreffion. When it was cuftomary to 

 ufe wooden blocks, the patterns were not enchafed in the 

 wood, but the wood was cut away in fuch a manner as to 

 leave the pattern in relief. It will be obvious that this 

 muft always be the cafe in i/oii-printing. 



When the mordant is ready, it is mixed up either with 

 flour -pafte, or w-ith a thick aqueous folution of gum arable, 

 gum fenegal, or gum tragacanth, and is then fpread upon 

 a piece of fuperfine woollen cloth, ttrained tight upon a 

 hoop. This is placed within another hoop, covered either 

 with fiieep-flcin or oil-cloth. Thefe hoops are both fo broad 

 as to give to each of them the appearance of a tambarine. 

 That which is covered with the woollen cloth is called a 

 Jieve., the other a cafe. The fieve within its cafe is now 

 placed in a fmall tub of gum-water, and is ready for ufe. 



Flour is an article of confiderable confumption with the 

 printers for making pafte. Some houfes buy twenty bar- 

 rels of American flour at once. Should it be mufty or four 

 from keeping, it is of little confequence for their ufe ; but 

 they are careful to buy none but fuch as has been made with 

 found wheat, ior if unfound it will be of no value for their 

 purpofes. 



Gum tragacanth is much dearer than the other gums 

 mentioned above ; but notwithftanding this, it muft be had 

 for fome ftyles of work, as no other will anfwer for any of 

 thofe colours or mordants which are prepared with nitrous 

 acid. A folution of gum fenegal. would be coagulated in 

 an inftant by any of thofe preparations. Of late years, an 

 article called Britifli gum has alfo been much in ufe for the 

 fame purpofc ; fo much fo that the making of it has 

 become a diitiiiiil trade. It is merely common ftarch pul- 



verized, and then calcined till it affumes a cinnamon-brown 

 colour. 



When the apparatus is thus prepared, the mordant is 

 applied by a brufl) to the furface of the fieve. This is 

 called tedrnig. 



It (hould have been remarked, that when a colourlefs 

 mordant, hke the acetate of alumine, is employed, the 

 workman generally mixes a little of the decoftion of Brazil 

 wood, or of any other fugitive dye, with it. This is called 

 Jighten'mg ; and is for the purpofe of making the pattern 

 more obvious to the workman, that he may fee its progrefs, 

 and the efficacy of the materials, as he proceeds in printing. 

 The manipulation may be thus defcribed. 



Taking the block containing the pattern in one hand, 

 the workman applies it gently to the iurface of the fieve, 

 fo that a fufScient quantity of the thickened mordant may 

 adhere to the figures. When the block is thus charged, he 

 applies it to the calico, and gives it a blow with a fmall 

 mallet, eitlier flightly or otherwife, according to the nature 

 of the pattern. 



This alternate application of the block to the fieve and 

 to the calico, is continued till the workman has gone over 

 the whole piece. In this way, feveral different mordants are 

 fometimes applied to the fame piece of goods. This is 

 indeed always neceffary, when the finifhed piece is intended 

 to contain a variety of colours, the different colours requir- 

 ing different mordants to fix them and render them perma- 

 nent. - 



The calico is now removed to a room called the ftove, 

 where a certain degree of heat is given to it by means of 

 flues, which go round the room on the infide, near the 

 floor. In this room, it is generally continued for at leaft 

 twenty-four hours. This is when common red-liquor has 

 alone been printed ; but if citric acid or ftrong miiriatc of 

 tin has been employed, lefs time is fufficient, and for the 

 latter feldom more than half an hour is allowed. The in- 

 tention of this is to evaporate the acids ufed in the prepara- 

 tion of the mordants, and which might otherwife injure the 

 texture, and alfo to fix the bafe more furely vx-ithin the 

 fibres of the cloth. 



In this operation, an attention to temperature is of the 

 utmoft importance. In general the room is kept at about 

 90° ; but an intelligent cahco-printer varies this according 

 to the nature of the work under operation. If iron-liquor 

 has been employed in printing the goods, it is an excellent 

 praftice to keep them for feveral days expofcd to the 

 atmofphere, after their removal from the ftove, as the 

 blacks, pompadours, olives, and indeed every other colour 

 prepared with that metal, will increafe in intenfity ; the 

 goods will clean better in the dung-veffels, as will be ex- 

 plained hereafter, and the colours ^^•ill rife higher and 

 brighter when tliey come into the copper of bark or madder. 

 The iron in an acetous folution is in the ftate of the black 

 oxyd ; but by expofure to the air it acquires a further dofe 

 of oxygen, and the more nearly it is made to approach to 

 the ftate of the red or peroxyd, the more fit it becomes for 

 a mordant in dyeing. It may be worth an experiment to 

 difcover whether the colours containing iron would not be 

 better if they were fuffered to be only a veryjliort time in 

 the ftove, but were hung up inftead for feveral days, ex- 

 pofed to a current of air at the temperature of the atmo- 

 fphere ; as the iron would thus acquire the oxygen flower, 

 and confequently would be fixed more firmly within the 

 cloth. 



When the pieces have been properly ftoved, they are 

 paffed, by means of a winch, through water at various 

 temperatures, with a little cow-dung mixed in it. Thi« 



part 



