According to the properties of vat dyes, the assistant dyeing method was selected
1、 Dyes with high aggregation tendency
It needs to be dissolved in the dye solution with high concentration of NaOH
Due to the low diffusivity, it is necessary to increase the temperature properly to accelerate the dyeing process
Without promoter
Nail staining
2、 Dyes with low aggregation tendency
The concentration of NaOH should be reduced properly
The dyeing temperature should be reduced due to high diffusivity
Add dye promoter
C staining