Each week, we are emailed with questions from our natural dye community asking simple and complex questions that we thought might be worth sharing. Here are a handful from this week answered by natural dyer in chief, Kathy Hattori, Founder of Botanical Colors:
What is the best natural fixative for cotton?
All tannins (chestnut, tara, myrobalan, cutch, etc) may be used to pre-mordant or mordant cellulose fibers but the recommended mordant is tannin and alum, and depending on the type of alum you are using, sometimes a post bath is also recommended. Instructions are given in our How To Section.
We are pleased to offer a plant-based mordant called Symplocos, which is sustainably gathered, sorted and ground into a fine powder. Symplocos comes from the leaves that are an alum accumulator, meaning that the leaves contain enough alum to use them as a mordant. So far, our experiments have yielded the best results with wool and silk. Check out our product page on Symplocos for more information.
What do you suggest is the best (easiest) way to dye black on silk yarn?
I would never consider black as an easy color as it is a lengthy and multi-step process. The simplest way is to combine a tannin-rich dye such as cutch, logwood or tannin with iron, but these combinations really produce dark grays. It is possible to get a very dark shade by using a combination of iron and logwood and a yellow dye such as fustic to counteract the purple shade of the logwood. Other recipes recommend creating a very dark indigo base and dipping to a navy shade, then layering logwood, iron and fustic on top of the indigo. Finally, some dyers create black by combining a dark indigo base with a strong yellow such as weld and a strong red, such as madder as blue, red and yellow will create a dark neutral. You can further darken the shade with an iron post-bath.