making - understanding natural dyes, a series - crocking & colour bleeds
have you ever bought a skein of richly dark indigo-dyed yarn, wound it up into a ball, and started to knit with it only to find your fingers turning blue? have you caked up a skein of madder-dyed yarn and found a ring of red dust left underneath your swift (and maybe even some up your nose)? have you knit up a colourwork sweater and blocked it only to have some of the more saturated colours bleed onto the undyed or paler ones? whoops, i suppose i should specify with that last one that we’re still talking about natural dyes here - that’s an issue to be aware of with all dyes, natural or not!
sometimes these experiences indicate an error on the part of the dyer - perhaps they didn’t strain their pots, or maybe they didn’t rinse the yarn adequately. and other times, it’s just a factor of choosing a richly saturated yarn. have you ever bought a good pair of jeans (or denim to sew your own pair) and had the indigo bleed onto your skin and furniture for a period of time even after multiple washes? or had your bright red yarn turn your blocking bath water a healthy cherry colour? or washed your socks in a big batch to find new splotches on some socks thanks to transfer from another sock that sat against them in the bath while you let them soak? again, we see all of these issues with both natural dyes and synthetic dyes, but we often hold natural dyes to a higher standard for whatever reason. here i’ll share my experience as both a professional natural dyer and long-time (also professional) knitter, using both my own yarns and naturally dyed and synthetically dyed yarns from others, to help you navigate these semi-common situations and either avoid them entirely or manage them after the fact.
some context
crocking is defined as “when excess dye sits on the surface of fiber or yarn and comes off when rubbed” (botanicalcolors.com) and occurs with both natural and synthetic dyes. you can mitigate this in some ways at the dyeing stage - scouring your fibres well, making sure your mordant isn’t flaking (can happen when you’re using the 50/50 method for reusing your mordant bath), rinse mordanted yarn prior to dyeing which will help remove any of these flakes, dyeing under the appropriate conditions (aka making sure your chemical bonds have set properly), and then for extra-dark dyes (typically the first bath if your dye pot is at a medium to dark depth of shade) letting the yarn dry first and then rinsing, which reduces washout and gives the dye a bit more of a chance to set.
this can all help, but it also doesn’t guarantee a no-crocking end result. so if you’re a customer and not a dyer, how can you reduce your chances of getting a skein that crocks?
don’t buy a saturated colour.
that’s it.
my experience over years as both a dyer and a knitter is that those richly saturated dark/extra bright colours are the ones that are most likely to crock, no matter how they’ve been dyed or what the dye source is (although those purples/reds/pinks/blues that are commercially so popular are often even more notorious for crocking than the yellows and greens). so if crocking really truly is a dealbreaker for you, buy less saturated skeins. they have generally come from exhausted dye pots and there will be less dye in the pot which removes the issue of “excess dye.”
well shit, ash, that’s not what i wanted to hear.
ok, fine. you’re not willing to give up those darker skeins (i get it, they’re pretty). let’s sort out what our expectations need to be in that case.
if dye comes out on your hands, you’re not gonna die. just wash your hands with soap and water after you finish a knitting session. it comes off easily and is not permanent. remember, your hands have not gone through the chemical bonding process to make the dye set, it’s just surface transfer. same goes if you’re working with wooden needles. i have personally never dealt with or heard from a customer who has experienced crocking transfer onto an item of clothing or furniture when their hands have been coloured by crocking, but if you want to be extra safe just in case, don’t wear white.
if you’re winding your yarn and find a fine dust on your work surface (or maybe even a whole flower head, cochineal beetle body, or leaf if the dyer used unrefined raw material), it’s not a sign that your yarn wasn’t dyed. as we discussed earlier [LINK], the dyes are the chemical compounds in the raw dye source, not the raw dye source itself. many commercial natural dye sources come in the form of powder/sawdust, and no matter how extensively a dyer strains their pots, some particles make their way through into the final dye pots and attach to the surface of the fibre only to come off when being handled. vacuum or sweep it up. it doesn’t harm you or your knitting and doesn’t mean anything about the dye results. if you cannot stand any iota of mess, you’re probably not working with minimally processed naturally dyed yarns anyway (but you can also ask your dyer if they use liquid extracts in any of their baths if you really want to try something and need to avoid any chance of mess).
always, always, always knit a swatch if you’re going to do any colourwork. and then block it the way you’ll block the finished item. sometimes dye transfer can occur in the blocking bath (with colourwork, i don’t like to leave an item in the water for more than 30 minutes just to be safe), and other times it can occur on the blocking mats while the damp yarns sit pressed against one another. it helps to know whether your yarn choices are likely to do this before you knit the whole thing. once that dye transfer has happened, you can’t undo it (i have seen people successfully use sunlight exposure to slightly “bleach” colours back to a less noticeable state, but you’re exposing the whole item in that case and you risk bleaching all the colours, so as a general rule i wouldn’t recommend it unless you’re super vigilant). if your swatch has some colour bleed happening, change your yarn plans. it is less annoying than dealing with it after the fact, trust me. that being said, it may not be an issue. i knit a colourwork sweater with a white undyed yarn as the base and a rich brazilwood and rich marigold as the contrast yoke colours and it’s been washed multiple times and never bled. swatch to be safe.
our final post in this series will go over the care and maintenance of your naturally dyed fibre over the longer term. slow fashion wardrobe for the win!
this post is part of a larger series on the basics and care for natural dyes. they’re not designed to teach you how to work with natural dyes, but rather the why behind them. if you’re dipping your toe into the waters (maybe with natural dyeing as practiceor natural dyeing 101 or the crush scholarship), it’ll give you a helpful basis from which you can start figuring out what other resources are legit and which are full of shit. if you want the full downloadable guide right now, you can find it with willow’s treats in the creative coven community.