How to Merge Double Knitting into One Layer Without Contrast-Color Bars

A new working yarn does not replace the loops already on your needle. If those loops alternate between two colors, joining them with one color still incorporates the old contrasting loops into the transition.

Purl texture makes this especially noticeable. TECHknitting explains that knit stitches emphasize the arms of the loops, while purl stitches expose their heads. At a color change, those exposed heads can appear as little bars of the previous color. Working a color change as stockinette places those bumps on the purl face. TECHknitting: Color, texture and ribbing without the icky dots.

Double knitting gives you somewhere to put those bumps: between its two layers. The practical approach is therefore to change each layer to the continuing color while preserving its outward-facing stockinette surface, then merge above that change.

Simply knitting every stitch across the original needle is a different operation. It leaves the original number of live stitches and does not explicitly join corresponding front/back pairs.

Begin with ordinary double stockinette whose stitches alternate between the front and back layers. Brooklyn Tweed describes each double-knitting pair as one front-layer knit stitch and its corresponding back-layer purl stitch; each chart square commonly represents that pair. Brooklyn Tweed: Colorwork in Double Knitting.

For the instructions below, use these labels:

• A: the color that will continue into the single-layer section.
• B: the contrast color being discontinued.
• Front layer: the layer whose outward-facing knit surface faces you at the start.
• Back layer: the layer behind it, with its outward-facing knit surface facing away.

Have spare needles or circular needles available, plus two working lengths of A. Using separate strands lets you prepare each layer independently. You will use only one strand for the final merge.

The worked example assumes complete stitch pairs across the entire width, without additional selvedge stitches. If your pattern has slipped, combined, or otherwise special edge stitches, identify them before proceeding. A two-strand edge loop is not automatically two separate layer stitches.

Stop after a completed double-knitting row and orient the work with the chosen front face toward you. Identify the next front-layer stitch and its back-layer partner by following their columns below the needle.

Slip front-layer stitches onto one needle and back-layer stitches onto another, alternating between them as you transfer. Slip purlwise to preserve their mounting, and keep each layer’s original stitch order. Do not sort by color: after a motif, either layer may contain both colors.

Working double-knit layers independently is an established option. TECHknitting demonstrates setting one layer’s stitches aside while working the other as ordinary stockinette, then returning to the held stitches. TECHknitting: Double knitting + working independent layers.

Count both needles before knitting. In an illustrative 24-stitch sample, you should have 12 front stitches and 12 back stitches. Mark the corresponding starting edges so you can reunite each front stitch with the correct back stitch.

Existing colorwork connections below the needles can remain in place. You need access to the live stitches, not two completely detachable pieces.

Work two rows of stockinette in A on each separated layer. This creates a short matching-color strip and returns each working strand to its starting edge.

With the original front face toward you, use this sequence:

1. Front layer, first row: Knit every stitch with A. Turn that layer.
2. Front layer, second row: Purl every stitch with A. Return the work to its original orientation and hold these stitches.
3. Back layer, first row: With its purl surface toward you, purl every stitch using a separate strand of A. Turn that layer.
4. Back layer, second row: Knit every stitch with A. Return it behind the front layer.

Both layers now have two additional rows, and every live loop should be A. Their knit surfaces still face outward. The color-change bumps belong on the inward-facing purl surfaces, following the stockinette color-change principle described by TECHknitting.

The two-row strip is an editorial choice for this procedure: it makes the matching-color preparation easy to inspect and brings the yarns back to corresponding edges. It is not a universal requirement for every double-knitting transition.

Before closing the layers, weave the discontinued B end and any unnecessary A joining tails into the inward-facing fabric. Keep the fabric relaxed while doing so, and leave one A strand available at the edge where merging will begin.

Hold the two loaded needles parallel, with their tips pointing in the same direction and corresponding starting stitches aligned. Keep the fabric’s original outward-facing knit surfaces outward; the purl surfaces remain together inside.

Using a third needle and one strand of A:

1. Insert the working needle knitwise into the first stitch on the front needle, then into the first stitch on the back needle.
2. Wrap A and draw one new loop through both stitches.
3. Slide both old stitches off their holding needles. Keep the new stitch on the working needle.
4. Repeat with each corresponding pair until both holding needles are empty.

This uses the paired knitting action shown in Purl Soho’s three-needle bind-off tutorial, with a crucial adaptation: retain every new stitch. Do not pass one new stitch over another, because that would bind off the edge. Purl Soho’s tutorial also uses a different fabric orientation for its standard seam; retain the outward-facing arrangement specified here. Purl Soho: 3-Needle Bind Off.

For the illustrative sample, 12 stitches on each holding needle become 12 live stitches on the working needle. Turn and purl the next row, then alternate knit and purl rows to continue flat stockinette.

The join can still have texture or thickness. The purpose of the preparation is to remove contrasting loops from the merge row, not to make the change from two layers to one structurally invisible.

Use this checkpoint sequence on a small swatch before adapting a full project:

Stage	Illustrative count	What to inspect
Double knitting	24 live stitches	12 complete front/back pairs
Layers separated	12 + 12	Matching starting edges and preserved order
Matching-color strips completed	12 + 12	All live loops A; knit surfaces outward
Merge completed	12	One retained stitch for every original pair
Several single-layer rows completed	12	Transition texture, width, and both faces

Halving the total live-stitch count does not mean deliberately halving the fabric’s width: the original stitches occupied two layers. Nevertheless, the width can change because double-knitting gauge and ordinary stockinette gauge can differ. The Knitting Guild Association emphasizes checking needle size and tension for double knitting, and TECHknitting discusses gauge adjustments when moving between double knitting and independently worked layers. The Knitting Guild Association: Double Knitting, TECHknitting: Working independent layers.

Wash and dry the swatch as you intend to treat the finished piece, then compare its widths below and above the merge. Choose the single-layer needle size from that result rather than automatically retaining the double-knitting needle size.

First locate the bars. Contrast at the original color-change boundary points to the preparation rows or fabric orientation. Contrast immediately beneath the joining needle suggests that some B loops remained when you merged. Scattered contrast visible through the fabric can instead be show-through from the other layer.

Check the following before continuing:

• A contrasting live loop remains: Undo the merge to that point and finish preparing the affected layer in A.
• A color-change ridge faces outward: Check that each preparation strip continues its layer’s stockinette orientation.
• The fabric pulls diagonally: Check that corresponding edges and stitch columns were aligned.
• Too few stitches remain: Check whether you accidentally passed stitches over as in a bind-off.
• The transition draws in: Compare gauge and the tension of the paired joining stitches.

If both original colors must reach the exact joining line, this same-color-strip method changes that design requirement. Test a direct join separately and inspect both faces; choosing one new working color does not remove the contrasting loops already present.

For a clean, inspectable transition, finish the color change while the layers still have an interior, confirm matching-color live stitches, and then merge one corresponding pair at a time. That sequence gives you a clear place to diagnose color bars before committing to the single-layer section.

• How To Knit: Colorwork in Double Knitting — Brooklyn Tweed
• Color, texture and ribbing without the icky dots—a mystery of knitting, explained — TECHknitting
• Double knitting + working independent layers — TECHknitting
• 3-Needle Bind Off — Purl Soho
• Double Knitting — Jennifer Kent, The Knitting Guild Association