What it is
Each knit stitch on the right side of stockinette looks like a small V. Duplicate stitch, also called Swiss darning, traces that V with a new strand of yarn, covering it so the stitch appears to be in the new colour. Because the shape matches the knitted stitch exactly, it blends in almost invisibly.
When to use it
- Single stitches and small details: eyes, highlights, the spots on a mushroom cap.
- A third colour in a row: stranded knitting is easiest with two colours per row; add the third afterwards.
- Names, initials and dates on a finished gift.
- Fixing mistakes in colourwork without unravelling.
How to work it
You need a blunt tapestry needle and yarn of the same weight as the knitting.
- Bring the needle up from the back at the bottom point of the V you want to cover, leaving a tail on the back.
- Go behind both legs of the stitch above: pass the needle from right to left under the two legs of the V directly above, following the path of the yarn.
- Go back down at the bottom point of the V where you started.
- Pull gently so the new yarn lies on top of the old stitch, not too tight.
To work a horizontal row, come up at the bottom of the next V to the left (or right) and repeat. To work a vertical column, come up at the bottom of the V above. Work horizontal rows in one direction and keep the tension even.
Following a chart
Knitting charts are drawn on a grid where each square is one stitch, so any chart can be worked in duplicate stitch: count the stitches on your knitting and stitch the coloured squares. Charts drawn on a gauge-correct grid, like the ones made in the knitting chart editor, show the motif in its true proportions, wider than tall, as it will look on the knitting.
Use a strand of contrasting waste yarn or locking stitch markers to mark the bottom row and centre stitch of the motif before you begin.
Tips for invisible results
- Match the yarn weight so the new stitch covers the old one completely.
- Do not pull tight; it should sit like a knitted stitch, not dent the fabric.
- Weave ends into the back of the duplicate stitches of the same colour, not into the main fabric, where they might show.
- Block afterwards: a light steam or wet block helps the new stitches settle.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Old colour shows through | New yarn thinner than the knitting | Use the same weight, or two strands of a thinner yarn |
| Stitches look dented | Pulled too tight | Ease each stitch so it sits like a knitted V |
| Motif sits crooked | Counted from the wrong row or column | Mark the bottom row and centre stitch before starting |
| Ends show on the front | Woven into the main fabric | Weave into the back of duplicate stitches of the same colour |
Duplicate stitch in charts
Many of the colourwork bands in the knitting pattern library have a few rows with a third colour, such as the black faces on the sheep band or the white spots on the toadstools, and suggest adding those stitches with duplicate stitch afterwards. It keeps the stranded knitting to two colours per row, which is easier to keep even, as explained in the guide to floats.