Prepared for Dye Garments (PFD)

There is often confusion between greige fabric, pfd fabric(prepared for dye), and finished fabric. Some people assume that greige refers to a color, but this is not the case. Greige is an unfinished woven or knitted fabric that hasn't been bleached or dyed. Attempting to dye greige fabric will most likely result in a poor outcome due to oils and waxes in the fabric from the weaving or knitting process. Therefore, fabric must be made PFD prior to dyeing. 

Scouring is deep cleaning of fabric or fiber and helps assure even color and good penetration of the dye, however, the pfd process on cotton is more complex than scouring. There are several auxiliaries needed for this procedure including a wetting agent, sodium carbonate(soda ash), stabilizing agent, peroxide, and caustic soda. After this process is competed the fabric will be off-white and is 'prepared for dyeing'.

If the fabric is not going to be dyed, but is going to be made white, an optical brightener is added to the fabric. This makes the color change from off-white to white and the fabric is no longer 'prepared for dye' due to the optical brightener that is now in the fabric. Optical brightener takes up 'dye sites' in the fabric making it difficult or impossible to achieve dark shades. Bright colors may also turn out duller than expected. Optical brightener cannot be removed. For these reasons, it is always better to dye prepared for dye fabrics and pfd garments.