The following is the optimal method of using the polyester deep-dyeing auxiliary Builder RN.

1) Circular dyeing

Water:	Water hardness is unimportant in deep-dyeing treatment with Builders RN and RN-1. Rather, its pH value is what is crucial.
After dyeing:	Acid neutralizing is necessary after dyeing and reduction clearing. Inadequate pH adjustment of the dyed fabric will influence the result of the subsequent deep-dyeing process.
Disperse dye:	The use of azo-based black dye in combination with anthraquinone-based blue will work generally well on the deep-dyeing effect.

2) Padding

Trough:	A smaller trough is preferred for better liquid stability. Builder RN and RN-1 maintain stability even when used in processing continuously for 24-hours.
Rolls:	3 (optimum)
Pick-up:	90% (optimum)
Non-touch:	For the prevention of unevenness

3) Intermediate drying

No tension:	Tension causes deterioration in deep-dyeing effects.
Temperature:	The depth of shade alters according to the drying temperature.

4) Curing

Shade may be varied by altering the tenter speed and temperature.

5) L*, a* and b*-values:

The depth may also be altered by changing curing conditions. The use of Builder RN or RN-1 guarantees an L*-value in the 9.0's.

Value correlation:	Shades appear pale even with an L*-value in the 9.0's, depending on the b*-value. When the L*-value is in the 9.0's, the a*-value should be kept at a certain level.
Optimum value:	Practical usage level information for Builder RN and RN-1 will be released in the near future.

6. Fastness (durability):

through curing

7) Final treatment:

Softening and anti-static treatments should follow the deep-dyeing process. A set of softening and anti-static agents is available and recommended for superior deep-dyeing results.