Dyes are available in market in different forms, such as- Fine powders, granular form, aqueous paste, liquid solution or dispersion. Commercial dye powders are not available in pure form; they usually contain various other chemicals (Admixtures) besides the principle dyestuff. These includes-
– Diluents such as salts or starch
– Wetting agents
– Impurities from manufacture
– Anti-dusting agents (oils)
– Buffers(sodium carbonate/phosphates)
– Shading dyes
Each company has its own unique standards or strength and are indicated by S/100. Here S indicates standard and 100 indicates its strength (usually for powder dyes). In paste dyes it is given as single strength, double strength or triple strength. Same dyes of different company have different strength for which one may require 10g of the dye of one company while 5g of different company.
For example, CI Acid Red 52 is rated 300%. This dye will produce a dyeing with a given depth of colour using a third of the weight of the standard product, which is rated 100%.