Textile printing has seen a number of innovations in printing methods since hand block printing were first superseded by machine methods. The changeover from traditional design work to using a CAD system can be a very positive experience. The main use of CAD system are the creation of original designs, or the interpretation of artwork supplied by customers, the latter being either painted artwork, fabric samples or possibly black and white film negatives.

Key words: CAD, printing, digital ink jet printing

Printing is an art. Printing can be defined as localized dyeing, which can produce designs of numerous innovative ideas and thinking. Traditionally, a technique for applying under pressure a certain quantity of colouring agent onto a specified surface to form a body of text or an illustration.

Fabric Printing Methods:

Blotch Printing: Printing instead of dying the ground color of a fabric. The result is that the reverse side of the fabric is typically white.

Discharge Printing: Using chlorine or other chemical to remove areas or previously applied color on a fabric and replace with areas of white patterns on a colored ground.

Dye Sublimation: Printing that occurs when a sublimation of dyes is transferred from a carrier roll and applied to the fabric/ substrate through the application of heat.

Rotary Screen Printing: Hollow, perforated nickel screen cylinders are prepared for each individual pattern color involved in a design. Color is then forced sequentially through the metal rollers directly to the surface of the fabric.

Screen Printing: Method of adding a print via one color per screen, one at a time.

Spray Jet: A Spray nozzle individually applies color directly to the substrate.

The major problem with all of the traditional printing methods, block printing, rotary screen, flat bed, engraved roller, etc., is that these methods rely upon the production of a design on a block, screen, or roller. The production of high quality screens or rollers is a complex, costly to make, costly to store, can become blocked or damaged and need replacement, and must be cleaned and dried after every production run. For all these screen and roller printing methods, over half of the total production time is expended on engraving and sampling. Other disadvantages are high wastage of fabric and print paste and high labour costs.

It can be readily seen that the analogue approaches in conventional textile printing methods now have some severe limitations for the modern printed fabric market. Printers now have to 'think digital' if they want to survive and prosper in an extremely cost-conscious and cost-competitive global market.

Digital ink jet printing has some considerable advantages over conventional textile printing methods because no screens or rollers are required. In digital ink jet printing, print heads, containing banks of fine nozzles, fire fine droplets of individual coloured inks onto a pretreated fabric. The print design is created digitally and the ink droplets are mixed together on the fabric surface to create the final colour.