Alkalis are water-soluble bases. Alkali is a general name given chemically to hydroxides of alkali metals such as lithium, sodium, potassium, cesium and rubidium and to ammonium hydroxide. All alkaline solutions contain hydroxide ions. If the acid and alkali solutions are mixed together, the hydroxide ions in the alkali solution react with hydrogen ions in the acid solution and form water and salt. Alkalis are normally readily soluble in water.

Alkaline dripping fastness is used to determine the extent to which these textile products lose color and stain on adjacent products when alkaline dripping occurs on printed or dyed textile products.

In the case of alkaline drip tests carried out by authorized laboratories, color fastness tests are in accordance with the following standard:

• ISO 105 E06 1 Textiles - Color fastness tests - Part E06: Color fastness to staining: Alkali

This standard describes a method for determining the resistance of the color of all types of textile products to the effect of dilute alkali solutions. According to the standard, three different tests are offered to ensure reliable results. Depending on the nature of the fiber, any or all of them may be used.

In order to evaluate the results of the test, the gray scale used in the fading assessment is used to determine the color change (TS 423-2 EN 20105-A02 Textile - Methods for determining color fastness - Section A02 - Use of the gray scale for the evaluation of fading).

In the textile sector, From raw materials to products ready to use many processes are applied. In the meantime, a variety of chemicals are used in dyeing, printing and finishing processes to give different properties to textile products. Although there have been some restrictions on the use of these substances in recent years, they have become an integral part of the finishing process.