February 2, Day 6
Our last full day. In the dye studio Michel is concluding with one of the most challenging colours – black. Most blacks are made with a combination of tannin and iron, but iron can eat away at the fibre and so there is a strict limit on how much can be used to obtain a colour.
Michel gives us another method whereby black may be obtained without using either iron or a mordant. This is a long process and it uses indigo, gall nut, lac, and tannic acid. It achieves a good black and it is very useful for wool. Because blacks are almost always built up through overdyeing, naturally dyed blacks are either warm or cool depending on the dyes that make them.
Before the day is over we review enzymatic scouring. In our post on scouring we encourage it, and Michel introduces wheat bran as a natural enzymatic method. As a quick test we tear a cloth in two; scour one half but not the other, and then place both in an indigo vat. The results are a little startling.
|Scouring tests. Without scouring on the left, with on the right|
Michel concludes the day with a short talk and sample book showing dye and mordant combinations that he had lab tested for fastness. He gave us recommendations and his thoughts on the best combinations.