Double Knitting technique

I have been working on some designs using double-knitting technique, to create a reversible colourwork fabric resulting in two layers of stockinette stitch back to back, but with the colours reversed. This technique produces a wonderfully smooth and even fabric compared with stranded colourwork, as there is no need to ‘float’ one yarn at the back of the work.  I have found, however, that the gauge tends to be looser than in single-colour stockinette, or stranded colourwork, therefore it is often necessary to drop to a smaller needle size in order to keep the fabric sufficiently dense and even.

There are several ways of casting on to start a double-knitting project. Usually the cast-on alternates between two colours of yarn. There are a few examples below, taken from other blogs and from Youtube, showing some popular cast-on methods.

Two-colour cable cast-on: this method uses the basic cable cast-on method, but alternating between two colours of yarn. There are a few online videos which describe this method – here is one example. This is the method described in the instructions for my Burano Cowl pattern. It produces a nice firm edge, although stretchy enough for purposes of the cowl. In the cowl pattern I alternate the yarns back and forth, largely to prevent them getting twisted (see an alternative video here which describes the edging effect you get if you deliberately twist the yarns).  In the ‘un-twisted’ method, it makes a difference, on one side of the knitting, which yarn is carried above and which one below, as shown in the photos below.

Two colour cable cast-on
In this example the blue yarn is always carried above the red yarn when alternating between colours (holding both in the same hand). In the first video link above, where the yarns are held in two hands, this is similar to holding the blue yarn in the RH and red in the LH.
Two colour cable cast-on
In this example the yarns are held the other way round – you can see the blue yarn actually appears closer to the needle, and the red yarn further away.

When knitting in the round, the edging above will actually appear on the right side of the work (assuming that is the side facing you for your first round, being the side formed by the knit stitches rather than the purl stitches) – see example below.

Burano Cowl cast-on edge
This shows the right side of the cast-on edge of the Burano Cowl where I alternated with the blue yarn always on top. As the first few rows of the pattern are mainly blue, this gave a slight stripe effect to the edge.  Other cast-on methods would work equally well, whilst giving a slightly different edge.

On the other side of the knitting there will be a ‘rope’ effect in alternating colours as shown in this photo:

Alternating colours in the two-colour cable cast on. Knitting flat, this would be the right side of the work, however if joining to knit in the round (e.g. for a cowl) this would appear on the reverse (or inside) of the work, as is the case in my Burano Cowl.

Two-colour alternating long-tail cast-on

This cast-on method produces a neat but stretchy edge.  There is a video by Sockmatician demonstrating this technique here.

Two-colour Italian Cast-on (as used for brioche knitting): see link here.

There is a video by Sockmatician showing his version of this method in action (called ‘Two-colour alternating invisible cast-on’): see link here. This video also shows how to perform the cast-on if you’re planning to use the ‘magic loop’ method of knitting in the round, with a circular needle much longer than the circumference of the knitted piece. This involves changing halfway through and casting on the remaining stitches on the opposite end of the circular needle.  One of my forthcoming cowl patterns uses this method of cast-on, but when it is knitted in the round on a 40cm circular needle which is short enough not to require the magic-loop method, it is not necessary to change halfway through and all the stitches can be cast on in the same direction.

The methods above produce a cast-on edge where both sides of the fabric are joined together. It is possible also to cast-on in a method which keeps the two sides separated (see, for example, this link from Arne & Carlos). In that case, the two sides of the fabric will only become interlocked once the colours are reversed as the colourwork pattern develops.

Finally, its worth noting that the number of stitches to be cast on is double the number of stitches which you want to see on each side of the fabric, this is because each pair of stitches represents one stitch on the front of the work and one on the back.

So how is double-knitting actually done?

The technique involves working pairs of stitches in two colours. Holding both strands of yarn behind the work, the first stitch in each pair is worked as a knit stitch using one colour. Both strands are brought to the front of the work and the second stitch is worked as purl stitch using the second colour. The purl stitch effectively acts as a ‘knit’ stitch on the reverse side of the fabric so that the reverse side looks like stockinette stitch. It is important to remember to bring both yarns back and forth when changing between knit and purl in order to prevent any strands of yarn from being carried across the outside of the work.

A charted pattern typically only shows the front side of the work – for each stitch shown it is therefore necessary to knit that stitch in the given colour then immediately work a purl stitch in the other colour used for that round. The other side of the work will therefore produce the same pattern in mirror image with the colours reversed.

Holding both yarns in one hand, or one in each hand, is a matter of personal preference. If holding in one hand, it is useful to alternate the direction in which yarns are swapped to avoid the yarns becoming twisted.  There is a link to a Youtube video here which shows double-knitting performed holding both yarns in one hand, and another one here showing the two-handed technique.

In the first of these two videos, the technique is used to produce a flat piece of work. The differences to note, as compared with knitting in the round, is that the initial slip knot is dropped from the needle (and subsequently undone) when knitting in the round, whereas this does not necessarily happen when knitting flat. The technique used for flat knitting in the video above shows the last two stitches of every row being purled together with both strands of yarn, and then slipped at the start of the next row. This keeps the edges joined together and neat.  Other methods exist (eg twisting the yarns together) for keeping the edges of the work joined.

Binding off

In my Burano Cowl, I use a standard bind-off method (see example here) alternating between knitting the first stitch of each pair in one colour and purling the second stitch in the second colour. This gives a firm edge, although I found it can be quite tight therefore a conscious effort may have to be made to keep the bind-off loose. Alternative bind-off methods do exist. I experimented with some of the more flexible bind-off methods used in conventional knitting but found they caused the edge of the cowl to ripple rather than maintaining a neat straight edge therefore not all bind-off methods are necessarily appropriate for double-knitting.

When using the two-colour Italian cast-on noted above, a very nice matching invisible bind-off can be produced by grafting using Kitchener stitch. This it not as difficult as it sounds and there is a very helpful video here which shows how to do this using a single knitting needle and a yarn needle. The method involves working a set-up round, where the first in each pair of stitches is slipped (with yarn at the back) then the second in each pair is purled. Following this, a long tail of yarn is cut and, with the yarn needle, both sides are grafted together.


There are more complex techniques which can be applied to double-knitting (eg increases and decreases) which are beyond the scope of this blog post. In the meantime, here are a few other links to double-knitting online resources:

Wikepedia – for a few historical references to the technique

Twist Collective – including comments about knitting different patterns on each side of the fabric

East London Knit – including an alternative method for casting on or binding off – with links to some video tutorials



Steeking a thumbhole

Some of my mitts patterns (e.g. San Marco and San Donato – coming soon) involve working a tube of stranded colourwork in the round, then creating a thumbhole using steeking.  Additional columns of steek stitches are created as the mitt is worked.

I prefer the crochet method of reinforcing a steek, and can thoroughly recommend the tutorial by Kate Davies which can be found here. I used this tutorial the first time I ever tried steeking, with total success. It is not really as scary as it might seem!

Anyway, for someone new to steeking these mitts are a great way of practicing the skill on a small project first, as the steeks are quite short.

The photo below shows the 7 columns of steek stitches worked as part of the San Donato Mitt:

Diagram 1

The technique involves first working a row of crochet stitches from the top edge of the steek down through the left side of each stitch in column 3 and the right side of each stitch in column 4. The crochet hook I used was 2.5mm (this works fine on stitches knitted with a 3mm or 3.25mm needle) and I used an fingering weight yarn which was stronger than the Spindrift used for the mitts (although for the San Marco Mitts I used the same Tukuwool fingering yarn throughout). See the Kate Davies tutorial for detailed explanations.

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The same steps are then repeated from the bottom to top, joining the right hand side of stitches in column 5 to the left hand side of stitches in column 4.

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Here’s a picture of the finished steek before cutting down the middle of the stitches in column 4.

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And here’s a picture of the steeks in the San Marco mitts, after a fair bit of wear, showing how the edges have not frayed.

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For greater detail on this technique, see the Kate Davies tutorial, noting that her example uses 5 instead of 7 steek stitches (therefore stitch 3 in my example equates to stitch 2 in hers).


Catching floats in stranded colourwork

When working in stranded colourwork using two strands of yarn, the yarn not being used is carried at the back of the work – commonly referred to as a ‘float’. If the pattern requires the floating yarn to be carried for too many stitches without being used, this can result in a long float which could get snagged when using the garment. For this reason it is usual for longer floats to be woven or ‘caught’ into the work every few stitches.

It is a matter of debate or preference how frequently to catch the floats. When using ‘sticky’ yarns which felt easily (such as Shetland), it is possible to carry floats across up to 7 or 9 stitches as the floats will naturally felt themselves into the fabric over time without causing a snagging problem.

There are many tutorials available online about how to catch the floats in stranded colourwork. Here is a concise one I found which shows the method when knitting with one yarn in each hand, as was used in creating the Torcello cowl (pictured above). (There are other online resources available which cover the method when knitting stranded colourwork on a purl row or where both yarns are held in one hand).

The yarn used in the Torcello cowl is a superwash DK weight meaning, firstly, that it does not felt and, secondly, that a float of 7 stiches will be longer than when using, say, a finer Shetland 2-ply yarn, due to the different gauge involved.  For this reason I caught the floats on the diamonds in the Torcello cowl in any stretch of 5 stiches or more. In the 5-stitch floats I caught the yarn mid-way and in the 7-stitch floats I caught the yarn either side of the mid-way stitch. I did this in order space out the positioning of where I caught the floats, as previous experience showed me that it could result in a line appearing up the middle of the diamond if all the floats were caught on the middle stitch of each diamond row. This photo shows the floats from the reverse side.


With hindsight, it may not have been necessary to catch the yarn on anything other than the 7-stitch floats. This would also have reduced the risk of the floating yarn from peeking through the pattern – if you look at the picture at the top of this post, you can spot a couple of places where the white yarn is peeking through the black pattern!


Mosaic inspired designs

I am currently finding a huge amount of pattern inspiration in the Cosmatesque mosaic floors of Italian churches! I’m currently producing the patterns for two designs – the first one is a cowl based on the diamond patterns of a floor in Torcello, Venice, and the second one is a pair of fingerless mitts inspired by a floor design in St Mark’s Basilica, Venice. The mitts use Tukuwool fingering from Finland, which I saw for the first time at Edinburgh Yarn Festival.




Venetian inspiration

For a long time I have been dreaming up designs which I want to turn into knitting patterns, inspired by places I have visited and things I have seen. My first range of ideas are based on the colours (including architecture, mosaics, textiles and reflections) of Venice. I am in the course of finalising and publishing a pattern for a cowl based on the marble and brickwork of the Doge’s Palace, using hand-dyed yarns. Here’s a sneak preview.