PRINTING ON CALICO. 



bark, figures in red or yellow are exhibited upon a blue 

 ground. 



In fome particular flyles of work, the operation of certain 

 colours is refilled by means of ftoppiiig out with wax ; but 

 this is too expenfive a method to be adopted often in thefe 

 times, when it is the objeCl of every manufafturer to finifli his 

 prints at the leaft poflible expeiice. [In printing thofe filk 

 handkerchiefs called Bandanas, a procefs called waxing is 

 ftill followed. It confifts in making a preparation of tallow 

 and rofin very hquid by heat, and in printing it in that ilate 

 with a block upon the filk. When fuch goods are pafTed 

 through the blue vat, thofe parts which are covered «nth 

 the tallow and rofin are preferved from the adtion of the 

 indigo, and remain white, while all the reft is dyed a faft 

 blue. The method afterwards taken to difcharge a part of 

 this blue, and produce yellow, orange, &c. will be men- 

 tioned hereafter.] Formerly this mode was very generally 

 pradlifed, and wax [in the Eaft Indies wax is ftill ufed for 

 preferving the whites in calico-printing] was confumed in 

 Tery large quantities by this procefs. [A very lingular- 

 looking fubftance was difcovered a few years ago near Stock- 

 port, which being handed about from one to another as an 

 undefcribed fubftance, created confiderable intereft in that 

 neighbourhood. Every body fuppofing it to be a natural 

 produttion, fpecimens of it were fent to a variety of perfons 

 into various parts of the kingdom, for their opinion and 

 analyfis, and among others a portion was fent to Mr. Parkes. 

 However, after every one had been bufily engaged in exa- 

 mination and conjefture refpefting this unknown fubftance, 

 it was announced, that fome feventy or eighty years before 

 a calico-work had ftood on the fpot where the article was 

 fou:id, and that this was nothing more than a large heap of 

 of the refufe compound of flour, wax, and gum, above-men- 

 tioned.] 



The reader will perceive that thefe rejijls are employed 

 for the purpofe of preferving certain parts of a piece 

 white, and of giving other varieties to thofe goods in which 

 blue is the predominant colour : but if the ground is to be 

 white, and the piece is only to have one fmall object [a 

 technical term, belonging to this branch of manufafture] 

 in indigo blue, fuch as a fingle fprig, then a different ma- 

 nagement is neceffary, and the colour is imparted by a pro- 

 cefs which is called pencil-blue. 



Here the indigo is deoxydized by means of orpiment, 

 which is a fulphuret of arfenic ; and formerly, whatever ob- 

 jefts were done with it were put in by means of a pencil : 

 hence its name, pencil-blue. [Pencil-blue is compofed of 

 the following ingredients, •u/'z. Ten ounces of indigo finely 

 ground in water ; twenty ounces of quick-lime in lumps ; 

 the fame quantity of potafh of commerce, or the impure fub- 

 carbonate of this alkali ; and ten ounces of orpiment. Thefe 

 proportions require one gallon of water, and the whole is to 

 be thickened with gum fenegal.] See Colour. 



Another kind of procefs remains to be noticed, called 

 chemicrJ difcharge-work. Here the cloth is firft dyed of 

 fome uniform colour, by means of a mixture of iron-liquor, 

 and fome one or more of the common vegetable dyeing fub- 

 ftances ; and calicoes thus prepared are faid to be dyed of 

 fclf-colours. They are then waftied and dried ; and when 

 properly preffed or calendered, they are fit for receiving any 

 pattern whatever, according to the artift's tafte or defign. 



This is generally effefted by means of the mineral acids, 

 which are previoufiy compofed for the purpofe, by diftolving 

 in them a portion of one or more of the metals, according to 

 the nature of the dye which is intended to be difcharged, or 

 of the colour to be produced. In doing this, care is taken 

 that the difcharging liquor be made fo as to be capable of 



diflblvmg the iron which is contained in the dye, and which 

 isalwaysufedm fuch quantity as to cove-, o- at leaft to 

 diiguife m a great meafure, the otlier colour or colours 

 which had been employed with it, and at the fame time to 

 aa as a mordant in beautifying and fixing thofe colours. 



Thus a piece treated with a decoaion of Brazil-wood 

 and dyed black by being padded [by the term paddin-r ig 

 underftood the operation of paffing the pieces from a roller 

 through a trough containing a folution of iron, or any other 

 mordant. Blotching is another term ufed in calico-printing, 

 and IS fynonymous with padding] with iron-iiquor, if, when 

 dried, it be printed with a peculiar folution of tin, the fer- 

 ruginous portion of the dye will be difi"olved, and the 

 printed part will inllantly be converted from a deep black to 

 a brilliant crimfon. 



In the fame way an olive-coloured calico, dyed in a folu- 

 tion of iron and a decoftion of weld, will as quickly be 

 changed to a bright pale yellow ; and the various drabs and 

 flates of every fliade which have iron in their compofition, 

 will undergo as fudden a change by the fame treatment ; 

 though the colour of the figures produced on them will de- 

 pend on the materials with which the cloths were originally- 

 dyed. Even the deepeft gold colours, or ftrongeft buffs, 

 if produced by iron only, may, by a peculiar preparation 

 of tin, be difcharged ; and fuch parts of the cloth as have 

 been treated with this metallic folution will be reftored to 

 their priftine whitenefs. 



By fimilar management, calicoes dyed of a light blue in 

 the indigo-vat, then run through fnmach and copperas, and 

 finiftied in a bath of quercitron bark and alum, may have 

 figures of a bright green imparted to them. Here the 

 green is originally formed by means of the indigo-vat and 

 the bark, though it is enveloped by the iron of the copperas, 

 which overcomes the other colours, till the folution of tin is 

 apphed, which removes the iron from thofe particular parts, 

 and gives a briUiancy to the remaining colours which they 

 would not othcrwife have pofleffed ; the tin being a power- 

 ful mordant for the bark, by which the yellow of the green 

 is produced. 



Again, a good felf-colour may be given to cahcoes, 

 merely by dyeing them in fumach and copperas, and then 

 running them through an alkaline folution of annotto ; and 

 here the figures produced by the apphcation of a colourlefs 

 folution of tin will be of a bright orange. But it is need- 

 lefs to enumerate m.ore inftances, as the workman accuf- 

 tomed to a dye-houfe will have little difficulty in varying 

 thefe in a thoufand ways, when he becomes acquainted with 

 the nature of the folution of tin which he employs. 



The whole of this, hovi-ever, refers to that branch of dif- 

 charge-work only, where all the purpofes arc attained by 

 diflblving the iron which makes a part of the colour that is 

 intended to be difcharged ; whereas, the finer and more 

 expenfive work is done in a different way, and by a procefs 

 which it will be neceffary for us prefently to defcribe. 



In the mean time it may be proper to remark, that there 

 is an objeftion to the particular kind of chemical difcharge- 

 work of which we have been fpeaking, namely, that it is 

 not perfectly faft ; that is, the goods produced in this way 

 wiU not bear fuch frequent wafhiug, as thofe which are 

 done by the bath of madder or bark. 



It is certainly an objeft of great national importance to 

 give a permanency to the calico-printing of the country ; 

 [to this end great improvements have lately been made in 

 the method of grinding madder-roots, by feparating the 

 inferior parts, and dividing the whole into two or three dif- 

 ferent qualities. Thus tiie printer is enabled to apply the 

 fineft, which in this way is made equal to Dutch crop- 

 madder. 



