Tech Tip: What is Double Knitting?

Double knitting creates two layers of fabric simultaneously, on one set of needles. Two layers provide warmth for cozy bed socks or double ­protection for cellphone or laptop covers, oven mitts and . . .­ ­spectacle cases.

Reversibility is another benefit: Double knitting looks like two pieces of ordinary knitting joined together, right sides out, wrong sides hidden. If you’ve ever thought a colorwork scarf needed lining, consider double knitting. For designers, double knitting frees two-color knitting from the constraints of stranding and floats, allowing big motifs, placed far apart and large areas of single color—no wonder many double-knit patterns use two colors!

Is double knitting hard?

Double knitting is a technique often relegated to the back of knitting books, in sections labelled “Miscellaneous” or “Other.” Maybe it’s just me, but I assumed this meant double knitting was something difficult, to learn later.

I was wrong. Once I started exploring double knitting, I realized that the movements of double knitting are easy and familiar—exactly the same as k1, p1 ribbing. If you can knit and you can purl, you can learn to double knit!

How do I get started?

Because double knitting has two layers, twice as many stitches are needed.

While most cast-on methods are fine for double knitting, casts-ons in alternating colors are not only decorative but make it easier for beginners to remember the k1, p1 double-knitting rhythm. The cast-on offered below (also used in the spectacle-case pattern) is very easy, but does result in twisted yarns.

A simpler method for casting on is worked as follows: Cast on half the required number of stitches, then knit into the front and back of all stitches on the first row, doubling the stitch count. The “back” stitches will make little bumps, showing where purl stitches will be needed in subsequent rows.

Double knit flat or in the round?

Double knitting can be knit flat (back and forth) or knit in the round.

Personally, I find double knitting in the round easiest: The procedures for joining to knit in the round, and for working each row, are no different to “ordinary” knitting in the round.

However, for flat (back and forth) double knitting, you must remember to cross the yarns at the end of each row, to enclose the messy-looking insides of double knitting, and to make a firm edge.

How is double knitting worked?

Whether you chose to double knit in the round or to knit back and forth, there are two things to remember when working double-knit stockinette stitch:

1. The basic motion is k1, p1, k1, p1, and so on. Although simple, it is vital to keep up this rhythm, no matter what. But k1, p1 usually makes ribbing—it is the use of two yarns, and how they are managed, that turns k1, p1 into double knitting.

2. Before every knit stitch, bring both yarns to the back of the work; before every purl stitch, bring both yarns to the front.
Keep the yarns together at all times, move both yarns back or forth for every stitch, even though only one yarn is used in actually working the stitch. The knit stitches create the fabric facing you, while the purls are creating the layer of fabric on the back side.

Keep the yarns together at all times, move both yarns back or forth for every stitch, even though only one yarn is used in actually working the stitch. The knit stitches create the fabric facing you, while the purls are creating the layer of fabric on the back side.

How do I read a chart?

With just two things to remember (k1, p1 rhythm; move both yarns together), double knitting seems easy, doesn’t it? But add colorwork charts, and it almost feels like trying to rub your tummy and pat your head at the same time.

Colorwork double knitting can have the same motif on both layers, in reversed colors; or different motifs on each layer! The first option is easiest for beginners, because only one chart is needed, providing you remember that:

Each square of the chart represents one knit stitch in the color shown on the chart, and one purl stitch, in the other color (this stitch will not show on the side facing you).

Initially, it can be confusing comparing your knitting to a chart, so here is some practice:

The swatch below represents the first 22 rows or so of the chart. In the swatch, on this side of the fabric, you only see half the stitches. The other half are on the needle, but the fabric they create is the second (or back) layer of the double knitting.

In large expanses of single color, stitches alternate neatly: knits (right-hand side) in the charted color, purls (left-hand side) in the other color.

But when the charted color changes, notice two stitches of the same color sitting together: on the right, a purl from before the color change and on the left, the first knit of the new color.

What should I learn next?

There is more double knitting than fits in a short FAQ. Next, you could practice double-knit increases and decreases (spoiler: rearrange the stitches) and make a hat. How about trying three colors, cables, knitting one sock inside another . . . there’s always more to learn!


Long-Tail Two-Color Cast-on for Double Knitting

Long-tail version: Determine which color yarn is used first in the pattern (C1) and proceed as follows:

Step 1: Make a slipknot using both color yarns held together, ensuring the slipknot lands with C1 on the needle first and the other color (C2) on the needle second.

Step 2: Pull 2 strands of C1 yarn from right to left between 2 strands of C2, using long-tail method, cast on 1 st with C1.

Step 3: Pull 2 strands of C2 yarn from right to left between 2 strands of C1; using long-tail method, cast on 1 st with C2.

Repeat Steps 2 and 3 until you have sufficient sts on needle (should be an even number, as stitches will be divided into two equal sections and st color should alternate).


Writer Ginevra Martin is a knitter and designer in Australia.


Learn to Double Knit!