my mother has asked me to ask “that weaver friend of yours” lol — do you have experience dyeing linen? what does the process look like for natural vs synthetic dyes?

happy to be that weaver friend of yours 🥰❤️ dyeing linen is basically the same as dyeing cotton or any other cellulose fiber, so any synthetic dye that works for cotton will also work for linen. a professional grade fiber reactive dye like procion mx or dharma's procion (here) dyes cellulose fiber without heat, and the process is quick and painless. it just involves a large bucket, water, the dye powder and the cloth you wish to dye. i have little experience with rit dye so i'm not sure if you'd need heat for that, but procion dye is higher quality, comes in a lot more colours than rit, and a 2oz container is like $2 usd and goes a long way

the natural dye process for linen takes a lot longer than the procion dye process and requires several steps. cellulose fibers really don't like to take dyes so you basically have to do a bunch of alchemy to convince it to do what you want (compared to protein fibers like wool and silk which love dyes and only need some gentle nudges)

naturally dyeing linen depends on the dye you'd wish to use, but the process is essentially: scouring, mordanting, and dyeing. it's really important that you scour linen especially because it contains a lot of pectins that prevent dye from penetrating the fiber, so a harsh scouring is best (ie. washing it with hot water and ph neutral soap, even to the point of boiling the cloth. linen can take a lot of heat and is better for it, cotton is more sensitive) you'll probably have to do this before dyeing it with the synthetic dye too for best results

most natural dyes require that you mordant the cloth before dyeing. some dyes don't require a mordant (indigo is the big one, but if you're working with onion skins or other materials that contain tannins this is also true. however mordanting the cloth before dyeing with tannins or even mordanting with tannins is still recommended for better colour performance long-term unless you're working with indigo in which case using a mordant can actually cause problems) but if you're unsure, assume that you need to apply a mordant. you essentially have to simmer the cloth in a hot pot with either a material that contains tannins (tannic acid), a natural bio-accumulator of aluminum (symplocos), or use a metal salt (alum acetate is best for cellulose, but iron and copper salts can also be used. the metal salts route requires more safety precautions esp if you use copper salt, you can't dump that down the drain) your choice of mordant impacts the final colour with different mordants shifting the chemical reaction that happens in the cloth when you dye it

with cotton and linen, after you use the mordant you need to use either a chalk or wheat bran bath to remove excess mordant from the cloth, esp if you use alum acetate, otherwise it can leave a whitish cast over the cloth and also impede dyeing lol. wheat bran baths tend to cause a warmer tone to the final dyed cloth, chalk baths cause a cooler tone. i only use wheat bran baths bc i prefer the warmth and i get the bran cheaply at my local punjabi grocer

only then can you dye the cloth, again unless you're working with a dye like coffee or tea or onion skins OR indigo. linen really doesn't like to take natural dyes unless you do all the above steps, it's stubborn. the dye process itself depends on what dye you use and you can do stuff like solar dyeing if you don't want to simmer it in a pot on a stove. if you plan to go the natural dye route lmk and i can send you some scans of a book i have that contains precise instructions for preparing linen for dyeing