T-increase is a symmetrical Double Increase, made from one stitch, using the Twincrease method.

Before publishing the Twincrease and related tutorials, I searched in books and on-line to find out all known types and methods for increases, and discovered that there really are a lot of Double Increases. After a closer look it became clear that more than half of them are not actually Double Increases at all.

Double Increase (DI) means that two new stitches are added to the knitting, which can be made between stitches (1) or from one stitch (2).

  1. DI from yarn over can be presented as 0—2 (0 sts to 2 sts)
  2. DI from a stitch can be presented as 1—3 (1 st to 3 sts)

There are other more complicated increases, like 3—5, but for the moment let us examine two basic types of DI. The first type, which is made between stitches, was already analysed in the Twinover article. Therefore here we will look only at the second type of DI worked from one stitch, or 1—3.

All Double Increases are divided into three groups: False DI, Semi-True DI and True DI. They are presented all together on one video 11 Double Increases, along with full tutorials for Semi-True DI and True DI, on YouTube and on Vimeo.

False DI

The most numerous group of increases, which are ironically NOT double increases, even though they are called centred Double Increases. In fact they are paired Single Increases, positioned on each side of one stitch. 

These two Single Increases can be made in many different ways, for example: 

  • Raised increase from the strand between sts;
  • Yarn over increase or M1 increase from backwards loop;
  • Bar increase – kfb – knit front and back;
  • Rib or Moss increase – k&p – knit and purl into the same stitch;
  • Lifted increase – LR and LL – lifted right and lifted left.

They are all Single Increases: they can be made anywhere, alone or paired, on each side of one stitch, or with two or more stitches between them. Therefore they are not actually Double Increases. The Single Increases were shown in the Twincrease article.

Chevrons knitted with paired Single Increases showing both raised increases and YO increases

These paired and mirrored increases are mostly used stacked one over another, to create raglan lines. In this chevron sample I combined ten variations – five worked as raised (bottom) and five worked from yarn overs (top). The bottom variations are very tight, while the top yarn over increases are looser. Nos 4 and 5 are variations of No 3, where the central stitch is worked differently:

  1. YO, k, YO – strands/YOs are worked open, two holes give a lacy look;
  2. M1L, k, M1R – strands/YOs are twisted in opposite direction, a small zigzags are appeared on both sides of the central stitch;
  3. M1R, k, M1L – as before, the reverse order of twists creates a raised central stitch; see how it is worked in the T-increase video, from 7:00. The link is below;
  4. M1R, ktbl, M1L – by knitting through the back loop the central st became a narrow cord;
  5. M1R, s1, M1L – by slipping the central st an even chain of elongated stitches emerges.

Semi-True DI

The next increases are made out of two stitches – from one current stitch and from one previous stitch (PS), which is the stitch below the stitch on the needle. Therefore those type of increases strictly speaking can’t be called true DI made from one stitch.

Three Semi-true DI, worked from two sts: the current stitch and the stitch below

To add extra stitches, we work into the stitch below, in two different ways.

  1. k, kPS, k – k current st, knit in the centre of the PS, knit current st again; when stacked they create a line of slightly “knotty” stitches, this is not a very common type;
  2. kRL, k, kLL – here the central st is worked only once between two lifted increases: knit into the right leg of PS, k1, knit onto the left leg of PS; when stacked they create a vertical line of accurate narrow holes, this is a very popular increase;
  3. kRL, ktbl, kLL – as before, but the central st is worked through the back loop; when stacked they create no holes at all – a pretty spectacular increase;
Chevrons worked with three Semi-True Double Increases

No 3 is a variation of No 2, which is found in The Principles of Knitting, the amazing book by June Hemmons Hiatt, p. 210 (version two). I recommend you give this variation a try.

True DI

And finally, real Double Increases, which are made using only one stitch, and when three sts are made at once, 1—3. I found three main types of these increases:

Four True Double Increases, worked from one stitch only
  • 1. ktbl, k, ktbl – often called Central Double Increase (CDI) – knit through the back loop, knit into the front loop and drop the st off; pick up the vertical strand between two new sts and knit it through the back. This increase creates small knot in the centre. It is not absolutely symmetrical because the base stitch is twisted, but this reduces the hole. Mainly used in lace patterns, less so for stacked raglan line.
  • 1a. k, ktbl, k – this is a very similar increase to CDI – first knit in front, then into the back of the stitch, drop it off; pick up the strand, which is hidden behind under the new sts, and knit it. This results in a small knot and a hole underneath. It is a symmetrical increase but rarely used because of the involved procedure.
  • 2. k, p, k –  work three sts in the same base stitch – knit, purl and knit, drop it off the needle. The result is a “knotty” horizontal bar and a big hole. This symmetrical increase can be used in lace patterns to add some structure.
  • 2a. p, k, p –  work three sts in the same base stitch – purl, knit and purl, drop it off the needle. It is very similar to the previous one.
  • 3. k, YO, k – knit the stitch, make a yarn over, and knit the stitch again, drop it off the needle. This symmetrical increase is very easy to do and it results in an accurate hole. Widely used for lace patterns and vertically stacked increases.
  • 3a. For example the [k, YO, k] has a variation called Porthole Eyelet. To work it, knit the first and last st into the PS. Or a better method: on the WS row, slip the central stitch with YO (as for Brioche), in RS row work knit sts into this stitch together with its yarn over.
Chevrons worked with True Double Increases

No 4 is a new True Double Increase: it is T-increase, which I developed last year. It resembles a Trident on the knit side.

T-increase – True Double Increase, knit side

After a lot of experiments with Twincrease, I discovered that it is possible to make three sts from one stitch using the Twincrease technique. There are a few variations, and T-increase is the purest one. It is an absolutely symmetrical double increase. It results in flat fabric and it can be used in many patterns, especially for raglan lines. It has a T-shape – three identical stitches positioned in one line, and two tiny holes on both sides of the base stitch. Best of all, it is very easy to work T-increase using the Twincrease method.

Raglan line worked with T-increase: a new Double Increase

How to work T-increase

T-increase is made in two steps. In the first row we create an elongated stitch by working “a double wrap”, and in the next row we make three new stitches out of this long stitch. T-increase has knit and purl variations.

T-increase made on the knit row

  • Row 1 (WS): purl up to the stitch where the increase should be, p1dw, complete the row
  • Row 2 (RS): knit up to the doubled wrapped stitch, kTin, complete the row

T-increase made on the purl row

  • Row 1 (RS): knit up to the stitch where the increase should be, k1dw, complete the row
  • Row 2 (WS): purl up to the doubled wrapped stitch, pTin, complete the row


  • p1dw – p1 with double wrap – purl the stitch wrapping the working yarn twice around the RN
  • k1dw – k1 with double wrap – knit the stitch wrapping the working yarn twice around the RN
  • kTin – to unravel the double wrapped st (dwst) slip it purlwise, wind long loop around the LN from front to back, work the first knit st from this position and drop the first loop off the LN, work the second knit st as ktbl by inserting RN into the loop from the front, do not drop it off the LN, work the third knit st inserting RN into the second loop as usual – knitwise, and off the needle
  • pTin – bring yarn to the front, slip the dwst knitwise and unravel the wraps, wind the long loop around the LN from back to front, work the first purl st from this position and drop the first loop off the LN, work the second purl as usual purl by inserting RN into the loop from the back, do not drop it off the LN, work the third purl st by purling the second loop through the back loop (ptbl)
  • YO – yarn over
  • ktbl – knit through the back loop
  • st (s) – stitch(es)
  • LN and RN – left and right needles

Please watch the detailed video how to work T-increase, knit and purl variations, in Continental and English style. This also includes the Centred Paired Increase [M1R, k, M1L] (No 3 from False DI), to compare it with the true Double Increase. The T-increase video is on YouTube and on Vimeo.

Two raglan lines to compare

If you know other True Double Increases (how to make 3 sts from 1 st), which I could have omitted from this article, please let me know in the comments. Thank you. 


  • Katarina Buss Big Book of Knitting, 1996 & 1999, p. 41
  • Montsey Stanly Knitter’s Handbook, 1986 & 2002, pp. 114-115
  • June Hemmons Hiatt The Principles of Knitting, 1988-2012, pp. 210-215

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