What function of a mordant?

A mordant is a substance used in dyeing processes to fix dyes onto fabrics or fibers. It works by forming a chemical bond between the dye and the material, enhancing the dye's adherence and colorfastness. Additionally, mordants can influence the final hue of the dye, making them an essential component in achieving desired shades and ensuring the longevity of the color. Common mordants include aluminum, iron, and tannin.