PRINTING: A process for producing a pattern on yarns, warp, fabric, or carpet by any of a large number of printing methods. The color or other treating material, usually in the form of a paste, is deposited onto the fabric which is then usually treated with steam, heat, or chemicals for fixation. Various types of printing are described below:
1. Methods of Producing Printed Fabrics:
Block Printing: The printing of fabric by hand, using carved wooden or linoleum blocks, as distinguished from printing by screens or roller.
Blotch Printing: A process wherein the background color of a design is printed rather than dyed.
Burn-Out Printing: A method of printing to obtain a raised design on a sheer ground. The design is applied with a special chemical onto a fabric woven of pairs of threads of different fibers. One of the fibers is then destroyed locally by chemical action. Burn-out printing is often used on velvet. The product of this operation is known as a burnt-out print.
Direct Printing / Extract Printing : A process wherein the colors for the desired designs are applied directly to the white or dyed cloth, as distinguished from discharge printing and resist printing.
Discharge Printing: In “white” discharge printing, the fabric is piece dyed, then printed with a paste containing a chemical that reduces the dye and hence removes the color where the white designs are desired. In “colored” discharge printing, a color is added to the discharge paste in order to replace the discharged color with another shade.
Duplex Printing: A method of printing a pattern on the face and the back of a fabric with equal clarity.
Heat Transfer Printing: A method of printing fabric of polyester or other thermoplastic fibers with disperse dyes. The design is transferred from preprinted paper onto the fabric by contact heat which causes the dye to sublime. Having no affinity for paper, the dyes are taken up by the fabric. The method is capable of producing well-defined, clear prints.
Ink-Jet Printing: Non-contact printing that uses electrostatic acceleration and deflection of ink particles released by small nozzles to form the pattern.
Photographic Printing: A method of printing from photoengraved rollers. The resultant design looks like a photograph. The designs may also be photographed on a silk screen which is used in screen printing.
Pigment Printing: Printing by the use of pigments instead of dyes. The pigments do not
penetrate the fiber but are affixed to the surface of the fabric by means of synthetic resins which are cured after application to make them insoluble. The pigments are insoluble, and application is in the form of water-in-oil or oil-in-water emulsions of pigment pastes and resins. The colors produced are bright and generally fat except to crocking.
Resist Printing: A printing method in which the design can be produced: (1) by applying a resist agent in the desired design, then dyeing the fabric, in which case, the design remains white although the rest of the fabric is dyed; or (2) by including a resist agent and a dye in the paste which is applied for the design, in which case, the color of the design is not affected by subsequent dyeing of the fabric background.
Roller Printing: The application of designs to fabric, using a machine containing a series of engraved metal rollers positioned around a large padded cylinder. Print paste is fed to the rollers and a doctor blade scrapes the paste from the unengraved portion of the roller. Each roller supplies one color to the finished design, and as the fabric passes between the roller and the padded cylinder, each color in the design is applied. Most machines are equipped with eight rollers, although some have sixteen rollers.
Rotary Screen Printing: A combination of roller and screen printing in which a perforated cylindrical screen is used to apply color. Color is forced from the interior of
the screen onto the cloth.
Screen Printing: A method of printing similar to using a stencil. The areas of the screen through which the coloring matter is not to pass are filled with a waterproof material. The printing paste which contains the dye is then forced through the untreated portions of the screen onto the fabric below.
Warp Printing: The printing of a design on the sheet of warp yarns before weaving. The filling is either white or a neutral color, and a grayed effect is produced in the areas of the design.