The choose of a good fixing agent removing agent is crucial to the repairing of the dyeing fabric. With the increasingly stringent customer requirements for dyeing quality, dyeing repair is inevitable, especially the repair of the neutral and dark color after its fixation, which is strictly required for the fixing agent removing agent. When we add color or overdye the light color fabric, we must eliminate the interference from fixing agent. Because if we overdye the fabric with the fixing agent, the discoloration is easy to appear. So we must remove the dye fixing agent and then change color.  (For the obviously deep color fabric, the removing of the fixing agent using fixing agent removing agent is less important. Because in the process of stripping and oxygen bleaching process, the dye fixing agent is easy to be removed cleanly and evenly.) This requires the fixing agent removing agent have good performance (1) the fixing agent removing agent will not decrease the brilliance of the fabric.  If the brilliance of the color decreases a lot, the bright-colored fabric will not easy to overdyeing(such as red).(2) little color change: The great change in color will cause the difficulty of overdyeing to the fabric. (3) no discoloration at the time of removing fixing agent.  If the discoloration appears, the repairing is failed. In addition, if the discoloration, brilliance, and the overdyeing process fail in the first time repairing, the following repairing will become more trouble, and the dyeing will fail.
When we choose the dye fixing agent removing agent, we need to consider the following 3 aspects.

I. The color removing property of the fixing agent removing agent
Principle and testing process description: the cotton fabric treated with oxygen bleaching, dye fixing agent 4%（o.w.f）40℃×20min, drying; fixing agent removing  agent 4%, 98℃×30min, removing the fixing agent of the fabric; Immerse the fabric(fixing agent is moved) and the same sample (after fixation but not removing the fixing agent ) into the same dyeing agent and dye into the same color (such as red light 0.05%), check the color depth of dyed samples, and determine the effect of the fixing agent removing agent. If the color is light, the effect is good. then test the removing the dye agent effect in the same bath in the process of oxygen bleaching and the removing the dye agent in the same bath in the process of stripping.

II. The breakage to brilliance
Choose red color fabric, dyeing, and fixing. And then remove the fixing agent using different colors, and then compare the brilliance of the fabric. If the effect of removing fixing agent is good, but the brilliance decreased greatly, the fabric will not get its original color.

III the changes of the brilliance
Choose deep blue color, dye, and fixing, remove the fixing agent, and check the changes of the brilliance. If the changes are large, it will be very difficult for overdyeing.