You would think, create a recipe, dye yarn, repeat, and nothing should ever change. But unfortunately it just isn't that straight forward. With the release of the McCoy line and the summer collection shortly afterwards I have found myself being asked about how to expect these yarns to perform differently. There are a ton of different ways to discuss the differences between these bases, but today I want to focus primarily on how they differ in terms of dye results and colours.
This post might find itself a bit long, technical, and with a tendency to ramble, but I promise that it is for good reason. Am I revealing some secrets, perhaps, but I want to be clear with the customer about the process and why they are seeing differences, rather than just the unfulfilling answer of “the magic in the pot”.
There are three components in this question: merino versus bfl, superwash versus untreated, and colourway depth of shade.
Merino versus Bluefaced Leicester
You might thing that this sums it up entirely, that this will be the most important difference in terms of colourways, but the reality is, it isn’t. As you will see from the photo below of unwashed and undyed skeins of McCoy and Bayfield Fingering there is a significant colour difference to the shades of the fibre. This is simply about the colour of the fleece that comes from the sheep, merino sheep are whiter and bfl sheep are creamier. In the majority of cases this doesn’t make a significant difference. You will find that merino colourways are clearer toned and bf are warmer. The only shades that you might notice a major difference is in very light ones like Vintage Lace or Sled Dog that will be heightened by the creaminess of the bfl or the silvery tone of the merino. All in all, it is the next point that makes the biggest difference between the two.
Superwash versus Untreated
This is where you are going to find the biggest difference between the lines (with one exception). The difference of the treatment of the yarn before it is dyed creates the most significant dye differences. All fleece from sheep is untreated regardless of the breed and will felt if machine washed and dried. Wool has small barbs or scales that will catch each other that creates the nice structure to finished garments but also causes it to pill. The process of superwashing wool removes these scales either by chemically removing or gluing down, functionally removing the inherent structure of the fibre. This is why you will find that your McCoy gauge swatches will relax significantly more than your Bayfield ones.
This change to the structure of the yarn dramatically causes differences to how the yarn absorbs dyes. All superwashed wools, in my experience, absorb dyes extremely rapidly while untreated ones take much longer to absorb the colours. This process is sped up once adding citric acid to set the dyes. We adjust cook times and when the citric acid is added to even things up as much as possible, but often that is simply impossible.
You will find because of this that lighter shades in superwash bases will be significantly more variegated and tonal than those in untreated bases. The dye is absorbed so rapidly, even without the additional of citric acid, that the tones of the recipes may be absorbed less evenly over the entire skein or batch.
Colourway Depth of Shade
Without question, you will find the most even results with very dark colourways. In order to achieve these shades a large amount of dye must be used, seems pretty self explanatory. With lots of dye in the pot there is more to go around to all the different skeins and strands so you will find the most even results. With extremely light colourways the dye creates simply just a skim of colour over the yarn so will not show major variation. The colourways that will show the most significant difference are those that are medium shades, they have a more significant colour presence without having a large amount of dye.
As you can see if this example using three similarly toned blues, an example of a very light depth of shade, medium, and dark. You will have more variegated results in the medium shade.
Colourways that fall under this category: Asclepias, Lichen, Green Glass, Surf, Vista, Aster, and Fawn, and Truffle. If you really hate variegated yarns … skip these shades in McCoy.
Note! While Bayfield Sock is a bfl base, it has been superwashed so will fall under its own unique category, but happens to be the most middle of the road yarn, which is why we choose to use it for photography on the website. It gives the most consistent and true results to what you will experience in the 10 bases.
From left to right ... McCoy Sock, Bayfield Sock, Bayfield DK. You can see here, Bayfield Sock is the middle of the road in terms of representation for dye results.