Madder is the most widely used plant extract from European sources for natural red shades. It dyes well on all fibers and with all mordants and is very lightfast and washfast. Madder is one of the oldest dye plants used. Its Latin name means ‘red of the dyers’. The roots of the Madder plant (Rubia tinctorium) are harvested after at least 3 years of growth. Once harvested, the roots are dried, which further develops the dye.
Madder Extract is an extract from Madder roots that contains both alizarin in free form and bound to sugar (Rubythric acid). Free alizarin not bound to Rubythric acid gives redder shades and with rubythric acid it gives more orange shades. If you want a Madder extract that has only free alizarin in it, then you should try the Madder Extract III. You need to use a lot of Madder to achieve reds.
I’m no chemist or scientist, but the Madder extract I have gets sticky when exposed to moisture, and I thought, ah-hah! Must be those sugars it contains! Madder extract III does not get sticky like that, and experiencing that Madder extract gets sticky, did make it stick in my mind that it made sense that exhausted madder dye baths can be used as a reduction source of sugars for an indigo vats. The bath may not contain a lot of color, but it still contains the sugars.
Madder is traditionally dyed with an Alum mordant , but I note that in Jenny Dean’s book, Colours from Nature, she says that all fibers can be dyed with Madder and just a tannin mordant. For more detailed information on dyeing with Madder, her book is a valuable resource.
Madder is sensitive to over-heating in the dye pot. Overheating, and simmering or boiling Madder root will result in browner tones. So, if you want browner tones, it’s not a problem, but if you were hoping for reds, or oranges, then, avoid simmering or boiling.
Madder will produce the best reds with an alum mordant and more purplish subtle hues by using an iron mordant in hard water that contains calcium. Madder prefers hard water, so calcium carbonate, often referred to as ‘chalk’ by natural dyers, is the principle mineral to create hard water, so add some chalk if you have soft water to deepen the shade.
Madder was used to dye the iconic British red military coats, red! If what I have read is true, the standard issued red wool coats were dyed with Madder and thus they were more of an orange-ish red. So, officers would pay to have their coats dyed with Cochineal, which would give them a more blue-hue or scarlet berry red.