Dyeing

Dye molecules are fixed to the fiber by absorption, diffusion, or bonding with temperature and time being key controlling factors.

[2] The earliest dyed flax fibers have been found in a prehistoric cave in Georgia and dates back to 34,000 BC.

[3][4] More evidence of textile dyeing dates back to the Neolithic period at the large Neolithic settlement at Çatalhöyük in southern Anatolia, where traces of red dyes, possibly from ocher, an iron oxide pigment derived from clay, were found.

An important characteristic was light-fastness - resistance to fading when exposed to sunlight using industrial techniques such as those developed by James Morton.

[9] The stage at which a product is dyed varies depending on its intended end use, the cost to the manufacturer, its desired appearance, and the resources available, amongst other reasons.

Dyes are classified according to many parameters, such as chemical structure, affinity, application method, desired colour fastness i.e. resistance to washing, rubbing, and light.

[26] Indigo dyes have a poor wash and rubbing fastness on denim (cotton), so they are used to produce washed-down effects on fabrics.

In contrast, vat or reactive dyes are applied to cotton to achieve excellent washing fastness.

Mordants were often required to alter the hue and intensity of natural dyes and improve color fastness.

Environmental concerns have now restricted their use, and they have been replaced with reactive and metal complex dyes that do not require mordant.

Space dyeing is a technique of localized color application that produces a unique multicolored effect.

The first notable industrial use of the technique was made by Benetton, which garment dyed its Shetland wool knitwear.

In the mid-1970s the Bologna clothing designer Massimo Osti began experimenting with the garment dyeing technique.

The complexity lay in developing both a practical and chemical understanding of how each fabric responded differently to the dye, how much it would shrink, how much color it would absorb, developing entirely new forms of quality control to verify possible defects in fabric before dyeing etc.

There are several terms associated with the process of dyeing: Affinity refers to the chemical attraction between two elements or substances, leading to their inclination to unite or combine, as observed between fiber and dyestuff.

[32]: 4 [33] Materials that exhibit bleeding tendencies may lead to the staining of white or light-colored fabrics in contact with them while in a wet state.

[32]: 150 [35] Stripping is a method used to partially or entirely remove color from dyed textile materials.