Mordant in Space Dyeing

The secret to space dyeing yarn involves the use of a special chemical called a mordant. Dye in the space dyeing is fixed on yarn with the help of mordant.

"A mordant is a substance used in dyeing that allows the dye to stick to the substrate. Mordants are metal molecules with a valency of two or higher and most commonly three."
The purpose of a mordant is to help permanently fix the dye to the yarn after the space dyeing process. Since different colors of dye require different types of mordants, this makes it possible to dye the same skein of yarn with many different colors.
Mordants are used to ensure the permanence of a dye. A mordant is a substance that is used in conjunction with the dye to chemically bond the dye to the surface. This is done through a coordination complex. In a coordination complex, metallic atoms from the mordant bond with the nearby dye, creating a powerful bond that water cannot easily disintegrate.
There are three ways to apply a mordant:

• Pre-mordanting (onchrome): The substrate is treated with the mordant and then dyed.
• Meta-mordanting (metachrome): The mordant is added in the dye bath itself.
• Post-mordanting (afterchrome): The dyed material is treated with a mordant.

True mordants must be metallic. Metal is needed to create the intense bond between the mordant and dye because, otherwise, the coordination complex cannot be completed.