Although a comparative exhaust dyeing method is always recommended for comparing two samples of dyestuffs, people in printing industry prefer to make strike off prints to compare the standard and sample.
Print Paste preparation for strike off:
Vinyl Sulphone dyes
H/P type of dyes
3-4% Sodium Alginate gel
Method of printing:
On a well mounted RFD fabric on printing table, using the above paste prepared separately for standard and sample, two strikes off would be printed with the test screens.
After the print, gets dried properly, the fabric will be passed through saturated steam chamber (in a Star Ager) at 1050C for 10-15 minutes or dry curing chamber at 1500C for 4 to 5 minutes. This is followed by hot wash, cold wash, neutralization with acetic acid 2gpl and 2 soaping, hot and cold washes.
Final pH is set at 6 by doing an acetic acid treatment at the end of all washings.