Interlocking Mattress Stitch Seaming Tutorial

There are many methods for joining your crochet pieces. Some can be decorative and stand out, while others are created as part of the design. But often, the seam is best if it is not noticeable. The interlocking mattress stitch is one that takes a little more time than some, but in my opinion, is well worth mastering. 

The interlocking mattress stitch leaves the sewing thread virtually invisible in the seam. Which is great when sewing pieces together that are different colors. 
This seaming method is also very strong. Perfect for when your project needs stability– a shoulder seam, for example. It’s also a great choice for items that will be handled often, like a blanket. 
I also choose the interlocking mattress stitch when using a heavier yarn. 

Advertising graphic with 2 crochet swatches being sewn together with needle.

the details

Interlocking is the key word. 
Each stitch is sewn from old to new to old again. Locking itself in place. 
Take a look at a hemline or seam from a commercially made item, the looping threads ♾️ are created by a serger│interlocking machine. This is the same idea behind the hand sewn interlocking mattress stitch. 

the tricky bits

The ‘interlocking’ of this stitch makes it a bit harder to get exactly right. It might take a little practice to keep tension even. But the extra time spent is so very worth it and your persistence will show with your finished piece. 

If some stitches are looser than others, your sewing yarn is likely to show through over time as the fibers relax with wear and washing. It’s important to keep this in mind as you are sewing your pieces together. 

the best part

Once you learn this interlocking mattress stitch, you’ll forever have it in your bag of tricks and if you’re like me, you’ll reach for it often. This is, honestly, my go-to stitch for seaming. It’s invisible, it’s flat, it’s strong, and it’s durable. 


interlocking mattress stitch

A stitchtorial, by Rebecca Velasquez

Having a length of yarn 4x length of edge on yarn needle, with WS facing, join at lower corners with a circular join stitch, as follows:

going under unused side loops of edge stitch, from R to L on First (right) Sq and then under the same loop on 2nd (left) Sq from R to L, pull yarn through, leaving enough tail for weaving.

Insert needle, under same loop as previously used on First Sq, R to L, completing a circular join stitch, pull yarn tightly closed.

Working under top loops only throughout, insert needle from R to L of first st of First Sq and first st of 2nd Sq, keeping stitching tight,

insert needle L to R under 2nd st of 2nd Sq, then back through first st of First Sq, pull tight.

Insert needle R to L under 2nd st of First Sq, then back through 2nd st of 2nd Sq, pull tight.

Pattern– In new stitch, out old.

Continue in pattern across edge to end.

After all stitches have been sewn across edge, complete a circlular join stitch by inserting needle under unused loop of side edge of last st on 2nd Sq,

then back through last st of First Sq,

insert needle under same loop as previously used on 2nd Sq, R to L, completing a circular join stitch, pull yarn tightly closed.

Weave in ends.

Shown Right Side

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Get stitchin!

Are you ready to take your new skill out for a spin?

Here are a few of my free patterns to get you going. 


Do you have further questions about this technique? Join the Facebook group and either myself or one of the other wonderful members can help!

Is there something specific you are wanting to learn? Please leave a comment here or in the Revel group and tell me. Hearing from you helps to guide me in what I should do next. I’d love to chat about possible tutorials and teaching topics!

About the yarn

If you, like me, tend to avoid bulky yarn because of the stiffness and heaviness that is often the result, I recommend you give hue + me a try.

This yarn is produced by Lion Brand, but is designed by Alexandra Tavel, a lovely knit and crochet designer. The blend of 80% Acrylic 20% Wool is wash & dryable. 

The wool adds a nice squishy factor to the yarn that keeps it from being a hefty, unmovable fabric.
Also, the colors it comes in…. dreamy, all matching, subtle and gorgeous.
shown right: Love Song & Werewolf

Lion Brand hue + me

Keep learning

Did you know I make Tiny Tutorials for many useful techniques, tips and tricks? 
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Stitch & Share

#LearnWithRevel and #RevelStitchtorial

If you’ve enjoyed this tutorial, please consider sharing your progress and awesomeness on social media. If you do, use the hashtags in all your postings so I get a notification and don’t miss it – I really do love to see all the amazing creations!

Rebecca's hand written signature.

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