Triple Check Knit

Triple Check Knit

Triple Check Knit 640 480 mathgrrl

Today we’ll take a break from digital 3D design and do some good old-fashioned analog knitting. Here’s a stitch we’ve been working with recently, in progress as part of a simple scarf:

If you think there’s something weird about that stitch, you’re right: If you look across each row you’ll see that… there really aren’t any rows? The stitches kind of zig-zag up and down as you move from one side to the other.

The really cool thing about this stitch is that it is completely reversible, and in fact looks exactly the same on both sides:

So what is this crazy stitch, and where did it come from? We call it the Triple Check, and it’s a stitch we made up to solve a design problem. Maybe it’s new, maybe it isn’t; we aren’t sure yet, although we haven’t been able to find anything like it on the web or in our knitting books. If you’ve seen this stitch before, please let us know!

Designing by Deduction

Our design problem was to find a simple knit stitch pattern for multicolor reversible scarves that we could knit during math talks and committee meetings. Specifically, we wanted a stitch that would satify all of the following conditions:

  1. Reversible, preferably identical on each side
  2. Uses multiple colors but NOT floats, double knitting, or carrying more than one strand of yarn at a time
  3. Must be a simple stitch with a short repeat that one could easily knit without looking or counting while at a math talk; no brioche or fancy stuff
  4. Preferably the knitting procedure would be the same on the right side and the wrong side, to avoid confusion/mistakes if knitting while multitasking
  5. Weaving in ends is tedious, so minimize the need for this
  6. Finished piece should lie flat and not curl up

Of course the first thing we tried was finding such a stitch in the existing literature; no need to remake the wheel if there are already perfectly good wheels! However, in this case our literature search came up short, so we wondered… could we construct a suitable stitch pattern by deducing certain things from our list of desired conditions?

Somehow we did; here’s how the deduction process panned out:

  • One way to satisfy the multiple-colors-one-at-a-time condition (2) is to use slipped stitches. We decided to riff off the slipped-stitches trick for knitting vertical stripes in the round, with each color traveling across the knitting one at a time, slipping stitches to skip over stitches in the opposite color. But in our case we wanted to have a reversible fabric, and to knit on straight needles.
  • A really easy way to satisfy the reversibility condition (1) is to use some kind of rib stitch. That would also have the added benefit of satisfying our lay-flat condition (6). We didn’t want something too stretchy so 1×1 rib seemed like a good idea.
  • Conditions (3) and (4) basically mean that we have to keep it simple, so we started thinking about the simplest possible way to have a 1×1 rib that slips over other colors. After a bunch of dead ends the most obvious thing ended up working: basically, doing 1×1 rib and then slipping twice to leave a gap for a piece of 1×1 rib in another color.
  • The key that made the whole thing come together was using three colors instead of two. With two colors on straight needles, you’d have to knit across and back each row to get back to the other strand of working yarn. But with three colors and straight needles, the parity works out perfectly: knit across with Color A and leave it there, then pick up Color B and knit back on the wrong side, then pick up Color C and knit across, and then pick up Color A from where you left it and bring it back along the wrong side.
  • The three-color method above also satisfies condition (5) because there is no need for weaving in ends every time you change colors; all the colors just travel up the sides of the work with no ends.
  • When you slip stitches, the carried yarn has to go somewhere. If it goes in front of a knit stitch or if its color peeks through another color, then your work is not going to look good. The final piece of the puzzle was to figure out how to slip stitches so that the carried yarn was hidden inside the work. We’ll show a picture of the method that ended up working after we describe the stitch.

Triple Check Stitch

Here’s the simple, reversible, three-color “Triple Check” stitch that resulted from our deductions:

  • In Color A, loosely CO a multiple of 4.
  • Pick up Color B and [K1, P1, s1wyib, s1wyif] to end of row.
  • Repeat: Pick up Color C and do the same four-stitch pattern for one row. Then pick up Color A and do it again. Then Color B. Then Color C, and so on.

All slipped stitches should be purlwise, whether the yarn is held in back (wyib) or in front (wyif); see the video Slip stitches wyib vs wyif for a demonstration.

Note that in each color we are only traveling along the knitting one time, in one direction; not going across the knitting and back again. At the end of the row just drop the color you are using and pick up the next color, which will be waiting for you.

Hiding the slips

So where is the carried yarn hiding under the slipped stitches? In the close-up image below we’re just done the s1wyif step, slipping a black stitch with the white yarn held in the front:

What happens next is that the white “yarn in front” strand needs to be wrapped over the black slipped stitch to the back of the work. Here’s the exciting part: When we wrap the white yarn over the black stitch, the carried yarn will make a white bump that lies exactly over an existing white bump from a previous perl stitch!

Every slipped stitch in the Triple Check pattern wraps over a bump of the same color in this way, either in front or in back of the work. The carried yarn under the slipped stitches is basically copying the “knit, purl” stitch of the 1×1 rib below it (which is luckily of the same color as the carried yarn), but without making any actual stitches. This color-matching on the slipped stitches is the secret sauce of the Triple Check pattern, since all of the slipped stitches end up invisible inside the work.

Triple W Stitch

The Triple W variant below is actually the stitch we discovered first (originally we called it “The W”), but it makes more sense as a variant of the Triple Check. The stitch pattern is pretty much the same as for Triple Check but twice as wide, with pieces of 2×2 rib followed by four slipped stitches.

  • In Color A, loosely CO a multiple of 8.
  • Pick up Color B and [K1, P1, K1, P1, s1wyib, s1wyif, s1wyib, s1wyif] to end of row.
  • Repeat: Pick up Color C and do the same eight-stitch pattern for one row. Then pick up Color A and do it again. Then Color B. Then Color C, and so on.

Triple Check and Triple W are good stitches for stash-busting projects that use up your random yarn scraps and leftovers, because you can change colors gradually as you knit. For a gradient/morphing look, change just one of the three colors at a time, leaving two of the colors alone for a while before changing again. Here’s a Triple W scarf-in-progress with a color-morphing rainbow look:

Again, if you’ve seen the Triple Check or the Triple W stitches before, then please let me know! These stitches are so simple that I feel like they have to exist somewhere, but I haven’t been able to find them. Or, maybe we found a piece of low-hanging fruit that everyone else somehow missed, stumbling on that rare combination of easy, interesting, and new? In any case, happy multicolor reversible multitask-knitting :)



  • Triple Check is now a project on Ravelry.
  • Holly (@antimonia on Twitter) found something by Nancy Marchant that looks just like Triple Check on one side. It’s brioche so much more difficult, and not identically reversible, but the front side matches perfectly!
  • Another good catch from Holly: You can get a reversible “tiny hearts” stitch by knitting two strands in white and one in red. After a couple of rows I started knitting/perling into the backs of the loops of the red stitches, to make them come to a sharp point and look more like hearts:
  • Trammell Hudson and Rod Bogart did some bind-off experiments and found that K1,P1 is a good bind off for the Triple Check:
  • More samples from Jacqueline Jensen-Vallin and Rod Bogart‘s wife. Love all the different color looks!
    Screen Shot 2018-01-28 at 12.31.29 PM
  • This design from Ellen Gormley uses a similar three-color staggered-row trick, but with crochet!

TRIPLE CHECK SWEATER! @adrian left this amazing photo in the comments of a beautiful triple check sweater :) :) :)


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  • WOW! I’m a fan already! I gave this a test drive and it is as advertised: easy, flat, WONDERFUL! Thinking of design ideas…thank you thank you thank you.

    • Thanks, Lisa! I love it when something so EASY just somehow works out.

      • I’ve shared this with both my knit circles and three different yarn shops. Every Knitter seems to have the same response: super cool, must try, give me the link.
        Spreading the joy and casting on!

    • I’ll admit that it looks good in three colours, but I don’t think you’ve stumbled upon something new or overlooked. What you have here, I believe, is nothing more than the double stockinette stitch. Well, not nothing more, adding two more colours really does make it quite nice.

      If you look up double stockinette, you’ll see that the procedure is the same. I’m sure this won’t thrill you to learn, but it is a form of double knitting.

      • Ah, for a minute I thought you had found it! But the triple check is more of a two-sided *rib* if you look at the pattern. And double-knitting double-stockinette makes true rows of knit stitches on both sides, where this one makes offset zig-zag rows.

  • Very cool stitch, and great explanation of your process!

    • Margaret, is that cone yarn in your profile photo? Does that mean that maybe you are a machine knitter? I am just getting started with that so if you’re an expert and like sharing tips then please let me know :)

      • Same Margaret you met at Magpie! Yes, it’s a big cone of Zephyr (laceweight merino/silk), for me it’s mostly been for lace knitting, and it’s been my avatar for years since my lotsofyarn blog days!
        I’m going to work on local resources for machine knitting more after the holidays. I’ve got one friend in Raphine (down I-81 from you) who’s been playing around with a new to her machine, so that might be a good contact.

  • This looks super-cool and I’m excited to try it! I was planning on going to the evening knit-along at one of the local yarn shops here in Amsterdam, and I’m going to get three balls and cast this on to see how it goes. I’ll ask around and see if anyone’s seen it — there’s a lot of brioche knitters at the shop I go to.

    Either way, I’ve always wanted to try some experimental knitting, so the fact that you came up with this on your own I think is really awesome. :D

  • Hello, I’m really interested in trying your pattern. Can you tell me if it would be able to convert to knitting in the round as I knit lots of colourwork hats.
    Thanks, Jacqui

    • I think you can adapt it if you get the count right… but I haven’t tried this yet. I’m hoping someone will jump in the comments with an answer to this one

      • I also saw this and immediately thought of a hat in the round! It seems to me the basic stitch as a multiple of four, and the alternating between each of three colors, should be no trouble to convert. The only problem I anticipate is that the stitches will lay on top of each other differently when you never turn back around. The simplest solution seems to be to alternate rows, where odd rows you do the pattern and even rows you do its complement (K for P, P for K, slip front for slip back, slip back for slip front), but that then violates the constraint of all rows being identical. Usually to convert things to in-the-round without losing the row-symmetry constraint you’d offset the rows slightly, working an odd number of stitches for an even repeat or similar, but since each row is a new color it seems like cutting rows between multiples of the pattern would result in a strange off-balance line in the stripes. For now, I’m going to get to work on the naive approach (alternating rows with their complement), but I’ll let you know if I work out a solution that doesn’t violate any constraints!

        • Update: I’ve worked it out! To knit this stitch in the round:

          Step 1: Start in a single-color rib or other single-color stitch to set the bounds; the edge will come out strange if you don’t set it before adding the other two colors.

          Step 2: On even rows, repeat K1 P1 sl1b sl1f

          Step 3: On odd rows, repeat sl1b sl1f K1 P1

          Where K1 and P1 are knit one and purl one, and sl1f and sl1b are slip one purlwise with yarn in front and slip one purlwise with yarn in back.

          This doesn’t have every row identical, but the only difference between rows is which goes first, so after the first stitch in the row (which you have to pay attention to anyway to get the color right), you’re back in the same pattern for every row. The result is gorgeous!!

          • This is awesome, thank you! If you email me a photo of the work then I will post it here as an update! (laurataalman at gmail)

  • hi

    I am new to colourwork knitting.

    So just to clarify, is this knit on circulars or dpn’s and you slide your needle after doing Colour A, in order to do Colour B & C across in the same direction ?
    Then once all the colours have reached across to one side of your work, do you turn your work and start again ?


    • This isn’t on circulars, just straight needles. I think you could adapt to circulars but this one you don’t do any sliding

  • Hi Mathgrrl! I was so happy to find your blog from SevenRavens777’s Triple Check Scarf 2019 project notes. I ran across it while looking at projects for the yarn she used.

    You may like to check out an obscure book called Reversible Two-Color Knitting by Jane P Neighbors from 1974. The main trick she uses is sliding stitches to the other side of the needle. The 2 simplest stitches she has are two color garter stitch and roll-over reversible.

    Two-color garter stitch is done by:
    cast on dark, slide
    1) light-knit, turn
    2) light-knit., slide
    3) dark -knit, turn
    4) dark -knit, slide

    This results in what she calls “opposite reversible” – the stitch is identical but all colors are reversed

    Roll-over reversible is done by:
    cast on dark, slide
    1) light-knit, turn
    2) dark- knit, slide
    3) light-purl, turn
    4) dark -purl, slide

    This is called an “upside down reversible”.

    There are 3 other stitches that are just combos of knit and purl rows. Then she gets into mixing in knits and purls in the same row. Next, she throws in slip stitches and then yarn overs. The next chapter is what she calls Chain Patterns which are some of the simple patterns as backgrounds with assorted vertical chains on the front and back. The last chapter of stitches is Reversible Geometrics which are more complicated combos of ribs and slipping. I’m not sure if they are any different from double knitting of the one color per row variety. For that matter, I think your Triple Check might be a form of double knitting but I’m not sure about the exact definition about what constitutes double knitting or not. Neighbors divides her Reversible Geometrics into short form and long form. It could be that her long form corresponds to double knitting but it is hard for me to tell because her terminology is not the same as modern usage. Or I just don’t understand knitting well enough yet.

    I really wish someone would redo this book with color pictures and better explanations.

    • This is AWESOME, thank you! I just ordered it and can’t wait for it to arrive. Based on one of the other comments I’m now thinking that maybe the Triple Check is two-sided 1×1 rib double knitting? That makes me think of some other generalizations so maybe there’s something cool to ponder there… Let me know if you want to write a book with me later :)

  • I must be having a brain cramp because I can’t get this to look like it does in the pictures. I’ve tried it three times, studied the pics, but still haven’t figured it out! Any tips on what I might be misinterpreting in the directions?

    • Sorry for the long time to reply! But I might suggest checking that all your slipped stitches are purl-wise (whether yarn is held in front or in back)?

  • Wow, this is amazing! Will be my next blanket for sure. I’ve been on the hunt for a pattern exactly like this. I found this link through knitting paradise, a little site used for questions and answers , cool stuff and pictures of all things knitty. Thank you very much for the fun to come!

  • I just want to start off by saying I love this pattern and it’s super easy to do! But I feel like I’ve run into a bit of a problem with the thickness though. I’m knitting a scarf and used a bulky yarn I had on hand because I just loved the color combos, but I’ve realized about a foot and a half in (it’s also about 9-10″ wide) that because of the double sidedness, it’s quite stiff and not very bendy. I typically prefer infinity scarves, but with the yarn I chose, I feel like it’s just way too stiff to be able to wrap around itself. I’ve thought about turning it into a cowl but it seems like it’s too tall for that? 9-10″ seems pretty tall. It wouldn’t be so much in the front but in the back, the neck just isn’t long enough for it to lay right. I saw from the pictures on your post that you knitted a rainbow scarf in the W pattern. It’s hard to tell, but it seems like you used a bulky yarn for that? Or am I wrong? Do you have any issues with it laying correctly with the stiffness if it is a bulky yarn? Or do you by any chance have any suggestions? I’m not quite ready to take it apart since I like it quite a bit. I had to take out my last work about 5-6 times though so if it needs to be done then….well…

    • I’m using worsted weight I think, so maybe that helps with the bulkiness. It is a fat puffy thing but for me it’s not stiff, even though I’m pretty tight-tension knitter. As for taking it apart, I think I must redo things 1000 times so I don’t have advice how to avoid it!

    • Hi Sarah. I also found it to be a “bulky” pattern. I upsized my knitting needles thinking I would have a looser scarf. I am knitting acrylic, worsted weight yarn and using size 10.5 (US size) needles. Nope, it is still pretty stiff but okay. I DO think upsizing needles is a good choice.

  • Hello! Just found this today, thanks to Pinterest. This stitch pattern is just so nice to look at. Thank you for sharing! Adding to my to-do list. :)

  • Will this work for circular knitting or no?

  • Do you have any suggestion for shaping? I am thinking of making a sleep bag with shaping for arms and shoulder straps.

    • That’s above my pay grade and skill level – I’m all about hacks and patterns but not like *patterns*. Check out Layne Berry’s idea for using this pattern in the round, maybe that will be of use :)

  • Carol Christensen June 30, 2020 at 1:45 am

    Love this pattern! As a retired high school math teacher, I am impressed you also used math to develop the pattern. Any reversible pattern is a hit in my crafting club, as many knit scarves for Special Olympics.
    A winner in so many levels.

  • I love this pattern. I was very impressed with the ease with which it knits up. Also, I was just knitting something similar (but with one colour) in that, it was like double knitting (thick and very warm) but much neater than double knitting, like yours but unfortunately was not reversible. This pattern fulfills my needs for so many projects… Thank you.

  • I’m not a very experienced knitter, but I have found your instructions so easy to follow!

    I did it initially as a swatch, and had to re-do, as I noticed I wasn’t following the instructions correctly. The I did it again properly and it looks beautiful! Not a front or back side, just all beautiful and flat, as it doesn’t curl up. Then I decided to start up a little vest for my nephew! I love it!!!!
    Please keep on posting!

  • Is there a way to do this in the round?

    • I think it would be no problem if you just make sure to get the count/parity right. I think in the round you’d have so many more options because you wouldn’t need the piece to be reversible, or the same on both sides.

  • I have really enjoyed knitting this pattern. It’s so beautiful. I’ve done 3-color and also I’ve got a variegated yarn and this works great to do this just back and forth — still these lovely squares that don’t curl.

    The more I work with it, the more I wish it could be shaped. Do you have any suggestions for increasing or decreasing?

    • Thanks, I’m glad you are liking it! Shaping…hmmm… if all one color then that might be easier, but I’m still not sure how or what might go wrong. I’d love to hear if you come up with something for that!

    • I think maybe if you kind of switch between the regular and the W one you could do increases and decreases that way? I’d imagine shaping would work however shaping works in any pattern with a 1×1 rib

  • I am having trouble making this work.
    Each color is worked only on one row correct?
    And do I knit the two stitches created by the yarn over as one or two stitches. I actually wish there was a video. I feel silly because everyone says it’s so easy. I must be missing something.

    • What yarn over? The pattern is K1, P1, s1wyib, s1wyif – there are no yarn overs. There will be floats in front of or behind the slipped stitches, but you just leave them there, you don’t knit them.
      Did you watch the video they posted above? You need to slip purlwise.
      Be sure to bring the yarn *between* your needles – if you bring the yarn over the right-hand needle that will cause a yarn over, maybe that’s where you’re getting them from.

    • There isn’t any yarn over/increase, only slipped stitches! I don’t know if that helps

  • Hi there

    I’ve tried it several times now and just can’t get it to look right. Could you post a demonstration video?
    I’m not an experienced knitter but I also think it has to do with my technique, I’m from the UK and my knitting/purling seems to be different.

  • I have 3 colors of DK cotton blend I bought for a top but now I can’t find a pattern. Would this stitch be too thick for a top? I love the way it looks! I’m thinking I could shape it by using different size needles. What do you think?

  • Just the perfect pattern for a scarf I am doing! Thanks a ton!

  • After many tryes half wrong i discover that very easy the stitch not prioch ,,,,,,hahaha ,,,,knit and purl with slip twice then 1k,1p, sl,sl,,,,

  • I found your sequence of stitches on Wikipedia. Only they have another set of 4 stitches and 2 colors

    • hey that’s cool do you have a link? (also if it’s only 2 colors and different stitches then what part is the same?)

  • It would be great if you could post a video of this pattern for novice knitters!!!

  • Thanks Laura – your instructions were so easy to follow – and I loved your rationale for your project! I had a big bag of stash wool and the colour combos worked a treat. I love the end result! So much that I’ve started another scarf in the same stitch. Thank you! :-)

  • This looks lovely, thank you so much for sharing it with us! I was wondering if you could describe how stretchy it is, maybe compared to a 1×1 rib?

  • Anyone who has tried this in the round for a hat – – what did you do for crown shaping (decreases)?

  • Bump!!
    Triple Check jumper/sweater :)

  • Hi, I was wanting to do this pattern in the round, and I know you reverse every other row to accommodate in the round, but I tried what I thought was the right way but it didn’t work. I was wanting to do the W pattern. Thanks.

  • Have made four scarves with different yarns and color combos. Each one turned out great. Would love additional tips and patterns for knitting in the round (like many others here) as well as increases and decreases…. If Adrian is willing to share that sweater pattern, I’d have anew favorite sweater!

  • What is s good way to bind this pattern off neatly?

  • All stitches are slipped purl-wise, as not to twist them, right? I am going to try using this to make a blanket for my daughter using stripes that gradually fade into each other. I think I can figure it out. I needed reversible and I’m so excited (and grateful) to find this. Thank you!

  • Thank you so much for this. I figured out to do solid color stripes that gradually fade into each other for a blanket for my daughter. It’s also reversible. :)

  • @mathgrrl, @Philip, @Mark.
    Thank you For the kind words =)
    No pattern I’m afraid, I didn’t use one as such as the tension square bore no relation to normal knitted fabric but I did use an aran pattern for help with increases/decreases, sleeve openings and neck etc.
    I made a tension square for normal aran knitting and one for triple check counted the stitches on each and did the mathematics. Also the finished fabric has a huge elasticity sideways so size down.
    No issues increasing/decreasing in the usual way but only at the beginning or end of the row remembering where you are in the 4 stitch repeat.
    No need for ribbing as triple check is a rib just use smaller needles for cuffs, waist and neck. The neck stands up on its own.
    After wearing it for a period I noticed because of its elasticity sideways it had shrunk in length so I turned the garment upside down and picked up all the binding off stitches and knitted an extra 2 inches on the round with no issues just like my Mother used to when I was growing up too fast!
    Because of the double thickness this is an extraordinarily warm sweater, good for polar exploration =)
    Jamieson’s of Shetland Heather Aran in 101 black, 102 Shaela, 103 Sholmit.
    Thank you mathgrrl for this intriguing stitch combination.

  • I have mastered the stitches…..Hoorayy. However I find that all three balls of wool tend to wrap around each other, is there a method to stop this happening. Many thanks.

    • I’ve tried being clever with some kind of method but what ended up working for me was keeping the three balls of yarn in three separate little bowls and just making sure to never get anything tangled in the first place. i put two bowls to my left and one to my right and pay attention how I turn each row

  • Can’t wait to share with my knitting buddies . Too bad theres no pattern for his sweater, it’s way cool.

  • I have a PASSAP knitting machine that was given to me by a friend whose spouse has passed several years ago. I only hand knit and have no desire to learn how to use the machine. I would love to find a home for it. If you know anyone who could use it, please let me know. It’s very heavy, has all its parts,in original box with books. Thanks!

  • I’ve been searching hi-n-lo for an easy baby blanket pattern and came across this one. So clever and so simple. Thank you!

    When blanket is done I’ll post in Ravelry. If your pattern is in Ravelry, I’ll be sure to tag it.

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