What Double Knitting Is and Why You'd Use It
Double knitting is a technique that creates a reversible fabric with two distinct sides — one pattern on the front, a different pattern (or the reverse of the same pattern) on the back. You work with two colours of yarn held together, and by switching which colour you knit and which you slip, you build both layers at once on a single needle.
The result is thicker than single-layer knitting, warmer, and finished on both sides without seaming. Many knitters use it for scarves, blankets, and garments where both sides will be visible. Because you're working two layers simultaneously, a double-knitted scarf takes roughly the same time as a single-layer one, but you get twice the fabric.
The main drawback is that it uses more yarn — roughly double — and requires attention to colour placement. If you're comfortable with basic knit and purl stitches and can hold two yarns at once, you can learn double knitting.
Key Takeaways
- Double knitting uses two colours of yarn held together, with one colour knitted and the other slipped on each stitch to build two layers at once.
- You cast on using both colours together, then work every row by knitting with one colour and slipping with the other, switching colours as the pattern dictates.
- The fabric is reversible, with the pattern inverted on the back side, and requires roughly twice as much yarn as single-layer knitting.
- Tension matters more in double knitting because loose stitches on the slipped side will show gaps; practice keeping even tension on both working and slipped stitches.
Setting Up: Casting On with Two Colours
Begin by holding both colours of yarn together as a single strand. Use a long-tail cast-on or any cast-on method you're comfortable with — the two yarns act as one for this step. Cast on an even number of stitches; most patterns call for 20 to 40 stitches for a practice swatch or narrow scarf.
Once you've cast on, separate the two colours. One colour becomes your "A" yarn and the other your "B" yarn. Tie a small knot or use a stitch marker to keep track of which is which — this matters because the pattern depends on consistent colour placement. Hold both yarns in your working hand the way you normally hold yarn for knitting; many knitters hold one colour over the index finger and one over the middle finger.
Before you begin the pattern, knit one plain row with both colours together (treating them as one strand). This gives you a stable edge to work from and makes the first patterned row easier to manage.
The Basic Double Knitting Stitch Pattern
Double knitting follows a straightforward rule: on every stitch, you either knit with one colour and slip with the other, or knit with the other colour and slip with the first. The pattern chart tells you which colour to knit on each stitch.
Here's the step-by-step for one row:
- Bring both yarns to the front of your work.
- For the first stitch, if the chart says "A", knit with yarn A and slip yarn B purlwise (without knitting it).
- Bring both yarns to the back.
- Move to the next stitch. If the chart says "B", knit with yarn B and slip yarn A purlwise.
- Bring both yarns to the front again.
- Repeat this pattern across the entire row.
The constant movement of yarns front and back is what creates the two layers. When you knit with A and slip B, the B yarn floats behind the stitch, forming the back layer. When you knit with B and slip A, the A yarn floats behind, building the front layer. Both layers grow together.
Reading a Double Knitting Chart
A double knitting chart looks like a regular knitting chart, but each square represents two stitches of information: which colour to knit and which to slip. Some charts use two symbols per square (one for each colour), while others use a single symbol with a colour key.
The most common format shows a square divided diagonally or uses two small symbols. One symbol means "knit this colour on this stitch," and the other means "slip the other colour." Always read the chart key before you start — different designers use different conventions.
Most double knitting patterns are worked flat (back and forth on straight needles) rather than in the round, because the colour switching becomes much more complex in circular knitting. Start with a flat pattern if you're new to the technique.
Keeping Tension Even on Both Layers
The biggest challenge in double knitting is maintaining consistent tension on the slipped stitches. If you pull too tight on the working yarn, the slipped yarn will bunch and create visible gaps on the back. If you pull too loose, both layers will look sloppy.
The slipped stitches should sit snugly on the needle without distorting the working stitches. Many knitters find it helpful to keep the slipped yarn slightly looser than the working yarn — not slack, but not tight. This takes practice; knit a few practice rows and check the back frequently to see how your tension looks.
If you notice gaps appearing on the back layer, your slipped stitches are too loose. If the front layer looks bunched, your working yarn is too tight. Adjust gradually rather than making a sudden change mid-row, which will create visible tension lines.
Binding Off Double Knitting
Bind off using both colours together, treating them as a single strand. Knit two stitches with both yarns held as one, then pass the first stitch over the second. Continue across the row until one stitch remains, then cut both yarns and pull through.
Some knitters prefer to bind off each layer separately for a more polished edge, but this is more complex and not necessary for most projects. A standard bind-off with both colours together creates a stable, reversible edge that matches the rest of the fabric.
Common Mistakes and How to Fix Them
The most frequent error is forgetting to bring the yarns to the front or back before slipping. If you slip a stitch without moving the yarn, it will twist and create a visible line. Always move both yarns before each slip stitch, even if it feels slow at first.
Another common problem is accidentally knitting both colours into the same stitch. This happens when you're not paying attention to which yarn is in your working hand. Mark your A and B yarns clearly — use a safety pin or clip on each colour — so you can see at a glance which is which.
If you drop a stitch, pick it up the same way you would in regular knitting, but be aware that you're picking up two layers. The stitch on the needle represents both the front and back layer, so one dropped stitch affects both sides. Use a crochet hook to pull the yarn through both layers.
Frequently Asked Questions
Can I use double knitting yarn instead of two separate colours?
Double knitting yarn is a single strand with two colours twisted together, designed for this exact purpose. It's easier than managing two separate balls because the colours are already paired and balanced. If you use it, you still separate the two colours as you work, but you don't have to hunt for matching shades.
What happens if I mess up a row in the middle of a pattern?
You can frog (rip back) to the mistake and pick up the stitches again, the same way you would in regular knitting. Because you're working two layers, pay attention to both when you pick up stitches — the working yarn and the slipped yarn should both be in the right place. If you're more than a few rows back, it's often faster to start over.
Is double knitting reversible if I use the same colour on both sides?
If you use the same colour throughout, you'll create a solid, thick fabric that looks identical on both sides. This is sometimes called "double knitting" in a looser sense, though true double knitting uses two colours to create distinct front and back patterns. A single-colour version is simpler and uses the same technique.
How much yarn do I need for a double knitting project?
Double knitting uses roughly twice as much yarn as a single-layer project of the same finished size, because you're building two layers at once. If a single-layer scarf calls for 400 yards, plan for 800 yards total (400 of each colour) for a double knitting version of the same length and width.
Can I do double knitting in the round on circular needles?
Yes, but it's significantly more complex because you have to manage colour changes as you move around the circle. Most patterns for double knitting in the round are written for experienced knitters. Start with flat double knitting first, then move to circular once you're comfortable with the basic technique.