SPECIAL TECHNIQUES
 
Resist Printing
 
In addition to normal printing techniques, there are special techniques available to the printer to produce unique effects on fabric.  The first of these is resist printing.  In this method, the fabric is first printed in a design with a chemical that resists dye.  The fabric is then dyed.  The resist will leave the fabric white or some other color in the print areas.  One of  the advantages of this method is that dyes with very high colorfastness can be used.  For cotton, resist printing can be performed with reactive,  vat, or naphthol dyes.  This method is very similar to the ancient method of batik.

 

 Discharge Printing
 
A second unique process is known as discharge printing.  In this method, the fabric is dyed to the required ground color.  Next, the fabric is printed with a chemical that selectively destroys the dye.  This leaves a white “discharge” design in the ground color.  As an alternative along with the discharging agent, a dye, which is unaffected by the discharge agent, is printed onto the fabric.  This yields special color effects of a colored discharge design surrounded by a stable ground color.  Using this method, it is possible to surround delicate colors and intricate patterns with deep ground colors.  Both discharge and resist printing have higher production costs than normal printing techniques.  However, designs not easily achieved with other methods are produced this way.  In the case of discharge printing, care must be taken to choose dyes that can
be selectively destroyed without extraordinary means and without damaging the textile fabric.  Discharge printing is routinely performed on cotton fabrics.
 
Flock Printing
 
A third printing technique is known as flock printing.  Here an adhesive is printed in a design on the fabric.  Next, the fabric is covered with cut fiber known as flock.  The fiber is then embedded in the adhesive by one of various techniques such as compressed air, the shaking process, or the electrostatic process.  Once the fiber is embedded in the resin, the resin is cured to firmly fix the fiber.  This technique produces a three-dimensional pile surface effect in a specific design on the
fabric.