TEXTILE PRINTING. The art of produc ing figured designs upon textile fabrics. by dye ing or staining, can he traced hack 4000 years to the early homes of textile wearing. in India and Egypt. Probably the earliest figured effects were produced by securely binding up spots all over the material so that the dye into which the fabric was afterwards dipped could not penetrate these places. Another method of producing white or uncolored spots was by applying fused wax, which, of course, was removed after the cloth had been dyed. According to Pliny, the Egyptians, from early times, were very skillful in the production of patterned cloth by apply ing or painting mordants on fabrics and then dyeing them. Another way of producing the same effect was the use of the stencil, on which the coloring material was applied with a brush. Painting. or making the designs directly with a brush, was a common method of producing figured textiles; most of the early figured tex tiles introduced into Europe were not really printed, but only painted fabrics. It is recorded that painted cloth, probably linen, was produced in London in 1110.
The printing block, in its most primitive form, was used in the Grient from the remotest times. In Europe it seems to have been applied to the printing of fabrics before its use in book-print ing was thought of. For centuries it was the only means used for producing figured not embroidered or painted. and it is still em ployed for producing special patterns. Upon the face of a block of some hard wood, 9 or 10 inches long, 5 or ti inches wide, and half as thick. the design was carved, a stout handle having previously been fastened to the block. Sometimes stout copper wire was bent into required shape and hammered into the block along the outlines of the pattern, which had been previously traced on the wood. The laidh upon which the printing was performed was a smooth flag of sandstone, covered with securely fastened blanketing. Over this table the fabric was spread. The thickened color was spread on a woolen cloth, upon which the printer applied the block and then stamped it upon the cloth. It required great skill and experience on the part of the printer to dip up the color evenly and in the right amount upon the block and then to apply it over and over, in exactly the proper place upon the fabric, until the entire surface had been covered with the design. Of course a separate block, with the proper portion of the design thereon, was required for each color, and between the applications of two suc cessive colors the cloth was thoroughly dried. The Perrotinc (so called from the name of its inventor) is a device for producing block print ing by machinery. The design is engraved in relief upon cast metal plates. It is now but lit tle used.
The invention of the roller printing press marked an epoch in the history of textile print ing. It made possible the production of pat terns complicated in design and coloring, at a cost so slight as to make it practicable to use them for the most inexpensive fabrics. The first
patents for roller printing were taken out in England in 1743 and 1772, and in France in 1801. The invention is usually ascribed to Thomas Bell. The roller printing press consists of a huge cylinder or bowl, revolving on its axis and carrying the cloth to be printed. While passing over this drum the material to be printed is brought into contact with another cylinder which carries the color and upon whose surface the pattern is engraved. The drum is covered or cushioned with several layers of a coarse cloth called lapping. Against this bowl is pressed the engraved copper cylinder, which receives the color from a wooden cylinder, covered with cloth and dip ping into the color-trough. In order to remove the surplus color from the copper roller, the so-called doctor is applied; this is simply a sharp blade which is pressed at an angle on the roller and serapes the surplus color from it. In order to remove any loose threads or fila ments, there is also a lint-doctor. The cloth to be printed passes between the engraved cop per roller and the bowl, and in order to have an elastic underlayer it is supplied with a blanket, which is usually of wool. To keep the blanket clean the back-cloth, of unbleached cot ton, is allowed to intervene between blanket and printing cloth. The three cloths (blanket. back cloth, and cloth to be printed) go through at the same time between the bowl and the print ing roller. The latter gives the color kept in the engraving over to the printing cloth next to it. This giving up is caused ( 1 ) by the pressure of the printing roller against the drum, and (2) by the action of the lapping and blanket, which, by forming a kind of elastic cushion, press the cloth into the engraved cavities of the roller and force the cloth to absorb the color, which is prevented from spreading by the pressure exerted at the same time. The copper roller is a hollow cylinder mounted on an iron man drel. It is sometimes engraved by hand, but more often by machine. The engraving is ac complished mechanically by producing the de sign in a small section by band. then reproduc ing it on a second piece of hardened steel, from which it is easily stamped over and over on the comparatively soft copper. By another method, known as the chemical process, the copper roller is covered with varnish through which the pat tern is cut with a pantograph The roller is then immersed in acid, which eats out the ex posed copper in the form of the design, after which the varnish is removed from the roller. The printed fabric is dried by passing it slowly over and near a series of steam-heated hollow cast-iron plates. As each roller prints but one color, there are as many rollers in a cylinder printing press as the desired number of colors. Great care has to be observed to keep the colors clear. In order that a dark shade may not soil a light one, the lighter shades are usually printed first and sometimes a plain starch roller is applied between the two.