Here’s a blog post that has been brewing for quite some time! In fact, it’s so in-depth I’m going to split it into two parts.
At RiverKnits, we pride ourselves on making exceptional quality hand-dyed yarns. That means when we notice something that could be better, or you tell us about an issue you’re having with our yarn, we take action. Today, I want to talk to you about crocking.
What is crocking?
There are two different types: dry rub and wet crocking. This article is going to focus only on dry crocking, because that’s the phenomenon we’re dealing with here. Dry crocking happens when dyed yarn or fabric transfers colour due to friction or rubbing. You may have experienced this yourself, knitting or crocheting with a yarn to find some of the colour has come off onto your hands.
We know this happens with some of our colours that have a lot of turquoise dye in the recipe.
What causes it?
There are a lot of different things that can impact how much crocking occurs, but first of all, let’s start with the basic chemistry. The dyes we (and the rest of the industry) use for wool are called Acid Dyes and they are molecules of various sub-types that bond with protein fibres in a weak acidic environment. Some dyes, such as reds and yellows, are quite small molecules. They quickly find a suitable bonding site on the fibre and don’t give up their place easily. Other dyes, such as neons and turquoise, are large molecules. These take longer to find a good “home” and subsequently don’t always form such strong bonds with the fibre.
We spoke to the chemist at our dye supplier to find out if anything else affects crocking. They said it’s mostly due to the size of the molecule and that those large-molecule colours are simply more susceptible to crocking. For us, it’s that beautiful turquoise. (We don’t use any neon dyes!) We had a chat about our dye process and confirmed we have already figured out other aspects that have a some impact on the outcome. It was good to hear that we are already doing everything we can to minimise the issue.
How much dye rubs off seems to vary from person to person. We’ve seen different makers work with the same yarn, from the same dye batch, with vastly different outcomes. One had no colour transfer at all, and the other had a lot! So some of it seems to be down to skin chemistry. Whether or not you use hand cream may have an impact and I’ve even noticed that crocking occurs less for me during one half of my menstrual cycle than the other.
Should you worry about it?
In short, no.
It can be pretty scary embarking on a project, especially a colourwork one, and then finding turquoise rubbing off on your hands. Naturally, we’ve found people worry that the turquoise will transfer to the other colours, or bleed out, when they block their project. The good news is: that won’t happen – phew!
I knitted a sample colourwork sock with that pesky turquoise and I filmed myself blocking it to show what should happen, even when the dye transfers to your hands during knitting / crocheting. You can watch that here.
As long as you soak your project in lukewarm water it will be fine. (30ºC is preferable, certainly no warmer than 40ºC.) Even if some excess dye rinses out, which is totally normal, the rinse bath won’t be hot enough for the loose dye to attach itself to anything else. You can use your favourite wool wash, or no wool wash, too.
You may have heard suggestions to try and fix “loose” dye by heating in an acid / vinegar solution. This is all very well if the dyer hasn’t properly fixed the dye, but if the only issue is crocking, then this method is a complete waste of time! (In fact it’s probably still not worth doing it if the yarn is oversaturated and won’t accept any more dye.) If your soak water is very heavily coloured, then you most likely do have a problem and should refer back to the manufacturer / dyer. At RiverKnits, we always ensure the dye is properly fixed and the yarn is thoroughly rinsed, so this shouldn’t happen.
Some colour transfer during knitting and crocheting is normal, particularly with turquoise and neons. Blocking and subsequent washes of the finished item should be done at 30ºC and will not cause any colour to bleed or stain other parts of the project.
What are our next steps?
We didn’t leave it here. Stay tuned for part 2 to find out what we did next!