Dyeing materials with plants is an ancient art practiced since biblical times. There are many plant materials that can be used for dyeing yarns and materials: roots, bark, leaves, berries, seeds, twigs, branches, tubers, and nuthulls, each capable of producing a range of colors with various mordants and yarns. In addition, when properly applied, natural dyes are fast, resisting fading due to exposure to sunlight.


Although there are many recipes for natural dyes, this experiment will only be concerned with a simple recipe for the preparation of a dye bath and the use or mordants to provide a variation in colors.


Mordants are chemical additives that sometimes help a fiber accept a dye that it might otherwise reject. (The word mordant comes from the Latin "morders" which means "to bite") Some of the more common mordants are listed in the table below.

 


Although you will be doing this process as a laboratory exercise, it is, not necessary to work in a laboratory or with highly technical equipment to do natural dyeing. You can easily work on a kitchen range, household-type hot plate or even an open fire and get equally good results. Remember to use soft water and utensils made of glass, stainless steel or enamel in order to get true colors. Don't forget to protect your hands with rubber gloves to prevent dye stains and to prevent excessive exposure to mordants.


Safety Precautions


  • Wear goggles at all times in the laboratory.
  • Wear rubber or plastic gloves when working with mordants and dye baths.
  • All the mordants used in this experiment can cause minor respiratory irritations if inhaled and possible mild skin irritation. In the event of skin contact, wash the affected areas with water.


Disposal


  • Dispose of all mordant solutions in the containers provided in the laboratory.
  • Solutions of natural plant dyes can be poured down the drain with running water.