27-09-2012, 10:45 AM
TEXTILE PRINTING
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PRINTING STYLES
Direct Style
Direct style of printing, in which colourants containing dyes, thickeners, and the mordants or substances necessary for fixing the colour on the cloth are printed in the desired pattern.
The printing of a mordant in the desired pattern prior to dyeing cloth; the color adheres only where the mordant was printed.
Resist Style
Fabric is first printed with a resisting agent, then dyed.
Produces similar effects to discharge printing.
Can use white or colored resists.
Can use dyes of much higher stability than those used in discharge printing and, therefore, much higher fastness can be obtained.
Discharge Style
Discharge printing is a method where a "dyed" fabric is printed with
discharging agents which selectively destroy the dye. A white discharge is produced.
An alternative method is to print along with discharging agents,
Non dischargeable dye which gives a colored discharge surrounded by a "ground" colour.
Advantages
1) Large areas of ground color possible
2) Delicate colors and Intricate patterns possible on deep ground color excellent depth and clarity possible
3) Higher production costs but long lasting, unique styles.
Block printing
This process, though considered by some to be the most artistic, is the earliest, simplest and slowest of all methods of printing.
In this process, a design is drawn upon, or transferred to, a prepared wooden block. A separate block is required for each distinct colour in the design.
A block cutter carves out the wood around the heavier masses first, leaving the finer and more delicate work until the last so as to avoid any risk of injuring it during the cutting of the coarser parts. When finished, the block presents the appearance of flat relief carving, with the design standing out.
Fine details are very difficult to cut in wood, and, even when successfully cut, wear down very rapidly or break off in printing. They are therefore almost invariably built up in strips of brass or copper, bent to shape and driven edgewise into the flat surface of the block. This method is known as coppering.
Block printing
If the pattern contains several colours the cloth is usually first printed throughout with one, then dried, and printed with the second, the same operations being repeated until all the colours are printed.
Block printing by hand is a slow process it is, however, capable of yielding highly artistic results, some of which are unobtainable by any other method.
ROLLER PRINTING
This elegant and efficient process was patented and worked by Bell in 1785 only fifteen years after his application of the engraved plate to textiles. Bell's first patent was for a machine to print six colours at once, but, owing probably to its incomplete development, this was not immediately successful, although the principle of the method was shown to be practical by the printing of one colour with perfectly satisfactory results. The difficulty was to keep the six rollers, each carrying a portion of the pattern, in perfect register with each other. This defect was soon overcome by Adam Parkinson of Manchester, and in 1785, the year of its invention, Bells machine with Parkinson's improvement was successfully employed by Messrs Livesey, Hargreaves, Hall & Co., of Bamber Bridge, Preston, for the printing of calico in from two to six colours at a single operation.