CALICO PRINTING. A means of producing decorative effects in the form of patterns or designs on cotton and other fabrics. The application of this art is not limited to the material generally known as calico, for almost all varieties of cotton fabric may be printed.
The effects produced are generally coloured, but many other substances besides colours are applied in printing, for example mordants to combine with colour principles in subsequent dyeing, "resists" to prevent dyeing, "discharges" to destroy the colour in certain places on already dyed fabric and substances capable of producing differences of texture and of lustre in the fabric.
The substance to be printed must either constitute or be made into a paste of such consistency that it will remain exactly where it is applied to the fabric and will not spread by capillary attraction beyond the limits of the design. With this object in view the sub stance is usually mixed with "thickening" which may be com posed of such materials as starch, flour, British gum, gum traga canth and less frequently albumen, casein or glue. Solutions used for the production of certain kinds of artificial silk may be already of such consistency that they can be applied directly for the pur pose of producing a lustrous film. The mixture to be printed is prepared in the "colour" shop of the printworks and whether its essential constituent is or is not colour the paste produced is fre quently known in the works as the "colour." It is the essential substance printed or the manner in which this acts during or following printing which determines the "style" of printing. Only by ingenuity in the application of chemistry to "colour mixing," is it possible to satisfy the ever increasing de mand for new and novel styles.
The local application of "colour" in the form of a pattern may also be carried out by the assistance of various instruments, but by far the most important is the engraved cylinder or roller. The first practically successful application of this form of printing machine was made in 1785 by Bell at the works of Livesey, Har greaves and Co., near Preston. Roller printing is applicable to almost all types of ornament and fabric, it is capable of depositing from one to sixteen colours in a single printing operation and in one working day 18,000 yards of cloth can be printed in one colour and 8,000 to 9,00o yards in 12 colours. The pattern is engraved intaglio in fine lines or dots on a copper roller or in the case of a multicolour design as many rollers are engraved as the number of colours in the design demands and in the form taken by each colour which it is intended to print. This method of printing enables much detail in very fine designs to be clearly represented.
The hand block on which the pattern is cut in flat relief is un surpassed for designs characterized by boldness and breadth of effect in rich transparent colours. By this method of printing which has been known from time immemorial such fabrics as cre tonnes, table covers, curtains and chintz may be produced with fine effect. Although the method is necessarily slow it has never been superseded by any form of machine printing for certain classes of work.
In the best types of work whether produced by block or machine printing, it is not possible to observe any stiffness in the printed parts of the fabrics, for all starch or gum is removed. Moreover the results represent the combined efforts of artists, skilled crafts men, chemists and engineers. (See TEXTILE PRINTING.) (E. HI.)