Invisible Seam (Reverse Mattress Stitch) – Joining Crochet Squares

I’ve been meaning to share some of my joining methods for ages.  I shall start with my Invisible Seam Reverse Mattress Stitch which joins squares flatly (no big ridges at the front or back)  and is a nice sturdy join.  It’s almost the same as the Mattress Stitch but is worked with the wrong sides facing and through the two back loops of each stitch.

invisible seam reverse mattress stitch
Invisible Seam – Right Side


invisible seam reverse mattress stitch
Invisible Seam – Wrong Side

I’ve used a contrasting yarn for the photographs so that you can see what’s going on and how the sewing disappears.

Begin with wrong sides facing and join yarn in the corner of each square.  Personally I use a figure of eight, leaving a long tail which I weave in later, but you can get the yarn started in whichever way you prefer.

How to Crochet…the Invisible Seam Reverse Mattress Stitch

Step 1:

Take needle through the two back loops of the first stitch of the left square, moving left to right…

invisible seam reverse mattress stitch


Step 2:

Insert needle through the two back loops of the opposite stitch on the right square, moving right to left…

invisible seam reverse mattress stitch

Repeat these two steps in the next few stitches and then pull the yarn to tighten the seam (this is when the yarn will disappear!!!)…

invisible seam reverse mattress stitch
Tightening the yarn


Continue Step 1 and Step 2 and remember to tighten the yarn every few stitches until the squares are joined and end yarn as you would normally.

This method works really, really well for joining different coloured squares together like granny squares or the Babette Blanket and you don’t have to be too concerned what colour you use to join as long as its fairly neutral.

Hope this makes enough sense to help some folks!  Give me a shout if you have any questions 🙂

Happy Hooking!

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  1. Paula Reply →

    I'll have to try this joining method. I usually join on the go as I find it easier and saves yarn but in some cases I think sewing the squares or other shapes together gives better results.

  2. Baban Cat Reply →

    Makes perfect sense! I've mostly used the double crochet join because I quite like the added texture. As you say this is great for joining different colours. I just have to remember it now!

  3. Ati. Reply →

    Thank you! I sewed my Babette together almost the same but took only one thread of the loop. It might be stronger when I take two 🙂

  4. Jo Bradford Reply →

    Thanks for this I am about to start joining my babette blanket, do yo have any tips for making sure the corners go together neatly – I have heard they can be problematic!

  5. WoolnHook Reply →

    The best way to make the corners neat is to block all the squares first. Or, when all the squares have been joined, sew a tight cross stitch through each corner to pull the stitches together. If you sew the cross stitch through the back loops on the wrong side it shouldn't be visible.

  6. Cathy Tucci Reply →

    Thank you so much for sharing your invisible seem. I'm working on my first blanket for my first grandson and didn't want a ridge when I joined the squares. The design is a gingham check and I'm using earth tones (brown, green, and tan). This is just want I needed to join them. Fifteen more squares to go and then I start joining!

  7. Anonymous Reply →

    Thank You Thank You THANK YOU!!! Im new to crochet and am making my son a patchwork quilt (a small one to begin with) and Ive been a good few hours trying to get my squares together using single crochet and sewing. Didnt like the results, stumbled across this page and had two squares looking fab within 10 minutes so thank youuuuuu loving the result xx love from helen in UK xx

  8. trishgager Reply →

    I am making a cancer blanket for someone which requires a ton of granny squares. I was looking for a seamless way to put them together and came across your tutorial. I am going to try it, but was wondering how you finish off.

  9. MicT Reply →

    Thanks so much for this tutorial. I'm making a Babette blanket and this is such a neat joining method and it really is invisible, which is brill as I can use one yarn colour to go up the row of different squares. And looking on your ravelry store I found a lovely scarf pattern too, so i have bought that and I am going to start hooking that alongside my Babette and other WIPs! Thanks for taking the time to provide this tutorial for free, it has really made a difference to the look of my blanket. 🙂

  10. ReniC Reply →

    I am so glad to see a pic-tutorial offered on this method to join squares. I have used it for years (too many to count) and it’s my favorite. Thank you for posting the How-To.

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