The padding style in calico-printing is intended mainly for the impregnation of cloth, in whole or in part,with mineral coloring substances. When the cloth is to be entirely colored, it is immersed wholly in a vat containing the mordant. When the color is to appear as a pattern on the fabric, the mordant is applied by a pattern block, or by the printing machine. In either case, the cloth is thereafter thoroughly dried, and washed in vari ous solutions, and then introduced into a vat containing the substance to form the color. Thus, if a piece of cloth is to be entirely impregnated with chrome yellow, it is first treated or padded in a solution of 8 parts of bichromate of potash a gallon of water, dried, and then placed in a vat containing a solution of 6 or 8 ozs. of acetate or nitrate of lead (PbOA, or PbONO.) to the gallon of water. The result is that the chromate of lead (Pb0Cr0,) is formed in the tissue of the cloth; and when the latter is washed and dried, the yellow color still adheres to the cloth firm and fast. To print a yellow pattern on cloth, 7 to 9 ozs. of acetate of lead, and the same quantity of nitrate of lead, are dissolved in a gallon of water, thickened with starch, and placed upon the cloth according to pattern. After drying, the cloth is first immersed in water contain ing a little carbonate of soda, and ultimately in a solution of bichromate of potash, when the pattern becomes fixed in bright yellow, insoluble in water. To produce Prussian blue on cloth, it is treated with acetate and sulphate of iron, dried, washed with warm chalk-water, and immersed in a very weak solution of yellow prussiate of potash. A pattern in Prussian blue is produced by printing a pattern in the cloth with the iron solutions thickened with gum, and thereafter proceeding as above. Chrome green is produced in a similar way, by using sulphate and acetate of copper, thickened with glue, and thereafter arsenious acid with potash; and so also other colors, such as iron buff or chamois, manganese bronze, etc.
The topical stylein calico-printing is the process whereby certain coloring matters which are insoluble in water, and cannot therefore be applied to cloth by the modes suggested under the madder and padding styles, are treated at once with the mordant, and the mixture by one operation transferred by block, or otherwise, directly on the surface or top of the cloth, and hence the term topical. Indigo, safflower, and arnotto are instances of such insoluble coloring substances; and when these and other dye-stuffs, such as log wood and Brazil wood, are treated with water, thickened with starch and nitro-muriate of tin (known as spirits) added, with occasionally a little of other salts, such as nitrate of copper, the result is the formation of spirit•colors, which can be printed on the sur face of cloth, and possess a certain degree of fixity. The permanency of these spirit colors, however, is very much inCreased, and the general appearance improved, by after wards subjecting the goods to the action of steam in a wooden chest or box, when the term is applied.
The resist style in ealico-printing is that in which certain materials are placed on the sur face of cloth, to protect it from the adherence of the mordants, and, consequently, to keep that part of the cloth from being attacked by the coloring matter. These materials are termed resists, reserves, or resist-pasters, and they are divisible into mechanical and chemical. The nzechanical resists are such substances as fats, resins, oils, wax, and pipe-clay. A common resist for silk and woolen goods is a mixture of 2-1- of resin and 1 of suet; and it is principally in the color-printing of silk and woolen dresses and hand kerchiefs that mechanical resists are employed, though they are occasionally used for the printing of cottons. The chemical resists may act on the mordant or on the color. Thus, if it be desirable to remove the mordant, and thus leave certain parts of the cloth unable to attach color, the printing of a pattern with some acid substance on the cloth will form with the mordant a soluble salt, which can be readily removed by washing, whilst the parts which have not been so acted on by acid are not dissolved away by the washing, and still retain the full power in the color-vats to cause the adhesion of the color. For this purpose, where an iron or aluminous mordant has been employed, it is
customary to print thereon in the requisite pattern, lemon-juice or lime-juice (containing citric acid), tartaric or oxalic acid, and bisulphate of potassa, or a mixture of two or more of these, thickened with pipe-clay, China-clay, gum-arabic, dextrine (British gum), gum-senegal, or a mixture of these; occasionally, chloride of tin is employed. Sulphate of zinc, sulphate and acetate of copper, and the chloride of mercury, are used to resist the adherence of indigo blue.
The discharge style in calico-printing comprehends the employment of similar materials to those used in the resist style, but after the cloth has been colored or dyed, and for the purpose of discharging the color, or bleaching the cloth at certain parts, according to pat tern. The dischargers for organic coloring matters are chlorine and chromic acid. The chlorine is employed in the form of bleaching-powder (q.v.), and the cloth already dyed is printed with a solution of tartaric acid (or other acid), thickened with pipe-clay and gum, then dried, and passed through a solution of bleaching-powder, when the decolor ation occurs, as already explained under BLEACHING. The chlorine is also applied by placing a number of folds of colored cloth between perforated pattern-plates, and sub jecting the whole to great pressure; a solution of chlorine (obtained by adding an acid to a weak solution of bleaching-powder) is allowed to percolate down through the per forations of the plates, and the cloth immediately underneath, so that only those spots are bleached, while the rest of the cloth is so highly compressed as to keep the liquid front coming in contact therewith. The well-known Turkey-red handkerchiefs are patterned in this way. The chromic acid is generally employed in discharging indigo color. The cloth, already entirely blue, is soaked or padded in bichromate of potash, and then an acid discharger printed thereon; and wherever the acid discharger (tartaric, oxalic, citric, or hydrochloric acid) comes in contact with the blue cloth containing the bichromate of potash, chromic acid is liberated, and destroys the color. Instead of acting upon the colored cloth, the discharger maybe employed to carry off the mordant. Thus, cloth treated wholly with a mordant, and thereafter printed with a pattern in acid, has the mordant removed at those parts where the pattern block has placed the acid. Mineral colors can also be discharged in a similar way.
The China blue or pottery style in calico-printing is a modification of the topical style, where indigo is deposited on cloth in the insoluble state, and is thereafter manipulated with, so as to impregnate the cloth with the indigo more or less strongly, and thus pro duce different shades of blue.
The above descriptions of the various operations in calico-printing have special refer ence to cotton cloth; and though many steps of the manipulative processes apply equally well to linen, silk, worsted, and de laines (worsted and cotton), yet considerable modifi cations in mode of treatment anti material employed are required in the successful color-printing of all texture containing animal fiber, such as silk and wool. Where the printing of such fabrics differs essentially front the processes already indicated, special reference will be made under SILK and WOOL. The different coloring mat ters employed in calico-printing being identical with those used in dyeing, will be considered under the general popular title DYE-STUF•S; and the mode of compounding these into the various colors and shades, will be more appropriately introduced under DYEING.