The root of the madder plant is surrounded by small fibers and is covered with black bark. Most of the pigment is contained in the red mass between the outer skin and heart of the root. Other dyes used in Rome include saffron which was collected from the pistils from the autumn crocus. Weld is another yellow dye source. With the invention of synthetic dyes, we are able to produce a much wider range of color as well as more vibrant and color-fast colors.
Synthetic dyes can reproduce the colors from natural dyes as well as hundreds more.
The synthetic dyes are inexpensive, not very harmful to wool fiber as some mordants are, quick and easy, and color-fast.