What are the most common mordant dyes?

Question

I have this project that requires the use of mordant.. what mordant dye can i use?

Answer 1

Most natural dyes require the use of mordants. Since most natural dyes will not bond directly to cotton or linen, these fibers are commonly mordanted with both alum and tannin, which form a bridge between the cellulose fiber and the dye molecule. Wool can be mordanted with the metal ions alone, without tannin. The most popular mordant for home use is alum, because, although alum can be fatal if swallowed, it's much safer than other mordants such as tin, copper, iron, or (particularly hazardous) hexavalent potassium dichromate. Commonly used natural mordant dyes include cochineal (Colour Index Natural Red 4), madder (Colour Index Mordant Red 11), and logwood (hematein, Colour Index Natural Black 1). You can buy these and other natural mordant dyes from a good natural dye supplier such as Aurora Silk or Earthues.

Mordant dyes, also known as chrome dyes, are heavily used in the textile industry to dye wool. The original mordant dyes were all natural dyes, but synthetic chrome dyes are in more common use now.  Chrome is commonly used as a mordant in the textile industry, in spite of its known hazards as a toxin and carcinogen, because chrome dyes provide a combination of level dyeing (with smooth even colors) and high washfastness (resistance to washing out) that is not seen with any other type of dye on wool. Other wool dyes are either level but not washfast, or washfast but not level. Some popular chrome dyes include Colour Index Mordant Red 7, Colour Index Blue 47, Colour Index Brown 27, and Colour Index Black 9.