As part of a continuing series, I'll be highlighting different special stitches and motifs. You may also want to read my previous spotlights on the Horizontal Chain Stitch, Cable Stitches, Bobble Stitches, Increasing and Decreasing Stitches and Basket Weave.
The invention of double-stranded loop yarns like Alize Puffy More and Bernat Alize Blanket-EZ Graph It yarns has made it much easier for loop yarn knitters to create two-colour designs, but these yarns still have some limitations. If you want to make a design with more than two colours, or want to incorporate more than just knit stitches for texture, double-stranded loop yarn can be somewhat restrictive.
To create a multi-colour design with regular loop yarn, you have a few techniques you can use. Which one you choose will depend on the type of design you are looking to incorporate.
STRIPES AND STRANDS
The easiest way to incorporate different colours in a project is to change colours in the same way that you would add a new skein of the same colour. My preference is to cut open the end loop of both skeins and then tie them in a knot and continue finger-knitting as usual. This video by Bambi Abi demonstrates this technique:
The other way to change skeins/colours that some people prefer, since it avoids the tying of ends, is to overlap a few stitches of the old and new skeins by double-knitting them, as shown in this video by Marly Bird:
You can use either of these techniques for creating colour-blocking and stripes, like in my Endless Waves Blanket or my Kids' Pumpkin Hat Patterns (where you change colours at the start of a new row):
... as well as for more eclectic scrappy-style projects where you are combining multiple strands of leftover yarn, like my Ripple Blanket and Oval Rag Rug Patterns (where you change colours at the end of each strand, regardless of where you are in the row):
FAIR ISLE
Fair Isle knitting is a type of traditional colourwork knitting that uses two different colour strands at a time. While the dominant colour strand is knitted in front, the secondary strand is carried behind, and then this process is reversed as the knitter changes from one colour to the other.
Doing this with loop yarn is complicated a bit by the pre-looped nature of the yarn, but a few years ago I did create a Fair Isle technique for loop yarn that I used in my Fair Isle Blanket and Mosaic Knit Style Blanket Patterns:
I could have achieved this look simply by double-knitting and alternating which loops of colour were layered on top, but that would have used up a lot of yarn! Instead, I combined a few techniques. First, I cut open some loops, so that I could use stretch the strands of yarn along the back, only using the loops of colour as needed. Second, I did double-knit yarn in cases where the colours alternated more frequently.
Cutting loops has to be done a bit strategically, because you only want to create enough loose yarn to stretch to the next stitch where you need a loop of that colour. You don't want too long of a strand of hanging yarn in the back, but it also cannot be too short or it will create too much tension. In order to prevent the strands from just 'hanging' in the back, I wove them in as I went, by sliding them between any double stitches. This created a back side that fairly closely mimics the look of Fair Isle with traditional yarn:
INTARSIA
Intarsia is a type of 'seamless' colourwork. The goal is to introduce a design of a different colour or colours within the larger project that appears 'inlaid'. This sort of colourwork is very popular for creating custom designs like logos, licensed characters or name personalizations.
The easiest way to 'cheat' this look is to just double-knit two strands of loop yarn at the same time, by layering the colour you want to show on top of your base colour. This allows you to continue your base colour for the whole project, and only adding the colourwork detail on top. The end result looks a bit like an embossed design. If your design is not too large, this option may suit your needs.
However, 'true' Intarsia knitting involves changing colours mid-project. Instead of cutting the yarn each time you change colours, you carry the individual colours of yarn upward to the next row as needed, and knit with two or more colours/skeins of yarn at the same time.
There are a few ways to do this, and it's up to you to choose which suits the needs of your design.
Seamed Intarsia
One very simple and very linear intarsia pattern is vertical stripes. In the custom blanket below, my customer wanted vertical columns of colour:
To achieve this look, I worked with five skeins of loop yarn - three pink and two grey (the green border was added after the centre blanket was completed). Starting from the bottom up, I knit a row of pink stitches from right to left. Then that skein became the pink skein for my first column on the left. As I knit from left to right, I joined each new skein along the divide of each column by double-knitting the two colours. As I changed colours I dropped the old skein and worked with the new skein, and so on. Basically, there are 5 'mini' blanket columns and each colour is only knit in tandem vertically.
This way of binding as you go by double-knitting the seams creates a very sturdy binding, but once again, double-knitting does use more yarn. There is actually a simpler way to bind two colours, and it will work for more fluid designs (not just straight lines).
Seamless Intarsia
The trick is to twist the two colours of yarn at the base to join them together.
You will still need to work with multiple skeins of yarn - if the colourwork motif that you want to add is in the middle of your project with a solid background, for instance, you will need different skeins of the background colour for the left and right side of the motif.
When you want to change colour to start your motif, cut a loop open at the end of the new colour skein and attach it to the previous skein (without cutting the previous yarn) at the base of the yarn in between the previous stitched loop and the next free loop.
Then, when it's time to change colours again, cross the base of the next loop on your current skein with the base of the loop on your new skein (image 2 below), and continue to twist the two loops until each colour returns to its original position (image 3). Then knit the next loop with the new colour (image 4).
And that's it! You'll continue with this same technique every time you change colour.
This technique provides the most seamless way to do colourwork, and you'll have much fewer ends to weave in later!