Mattress Stitch - How to Seam Knitting Easily

If you are knitting anything which is made up of separate pieces joined together, whether it is a garment, a cushion, or a toy, it will be useful to learn how to do the mattress stitch. This stitch is also known as ladder stitch, because of its appearance, which looks like the rungs of a ladder before it is pulled closed completely.

Mattress Stitch Tutorial

Mattress stitch creates a lovely, invisible seam on the right side of knitting and crochet. Although invisible on the right side, you will be able to see a little ridge of vertical seaming on the wrong side. To work mattress stitch, you need both pieces to have the same number of rows.

Supplies For Mattress Stitch

• Knitted or crocheted fabric
• Yarn needle - A blunt tapestry needle or darning needle is best so that it doesn’t split your yarn.
• Yarn for seaming - You will need approximately double the length of the seam.
• Scissors

How to Do Mattress Stitch Seams On Stockinette Stitch

Here are the step-by-step instructions for joining two pieces of fabric knitted with a stockinette stitch.

• Thread your yarn needle with matching yarn, or use a long tail left over from casting on.
• Lay your pieces to be seamed out flat, right next to each other, with the bottom edges closest to you. You will work this seam from the bottom up.
• Pull the edges of your knitting out slightly, to open up between the stitches.
• Find the running yarn between the first and second stitches on each piece.

• To start, work through the threads in your cast-on row.    
• Secure your thread (if not using a cast on tail).
• Work a figure of 8 for your first stitch.

I have used a darker pink contrasting yarn thread to make the sewn stitches stand out. But you should use the same yarn for an invisible seam.

• Pick up the first running thread on the right-hand or opposite side (this is the thread between the first and second stitches on the RH side).

• Now find the corresponding running thread on the left-hand piece. 
• Bring your needle under the thread, then pick up the corresponding running thread on the other piece.

• Work back and forth, from side to side, always making sure you are picking up the thread from the same row of knitting on both pieces.

• Every inch or so, pull your thread up to pull the two pieces of knitting together. Don’t pull it too tightly, or your knit fabric will pucker up and form gathers.

• When your sides are completely joined, tie off the end of the yarn you have used for stitching, and weave any loose ends through the ridge on the wrong side.

All those dark pink stitches have disappeared! Done in a matching color, you will get an invisible join on the right side. Here is how the front looks

Here is how the back of the mattress stitch looks. See the ridge formed in the center.

Mattress Stitch On Striped Stockinette Stitch 

When you are working with stripes or any kind of color work, the most difficult part is making sure that the colors line up perfectly. If you are careful about picking up the running thread between stitches precisely, row for row, this will work itself out perfectly.

Mattress Stitch On Reverse Stocking Stitch

This is a little more complicated because you have to alternate between the ‘mountains’ and ‘valleys’ of the stitches. If you look closely at the purl side of the knitting, you will see that some stitches curve downwards, with a peak in the middle, like mountains, and others curve upwards like a valley, or a smile.

• Align your knit pieces and begin, as described above on your cast on row.
• Then slide the needle through the first lower (valley) bar or running thread on the right-hand piece.

• Now cross over to the left-hand piece and slide the needle through the first upper bar (mountain) thread.

• Keep alternating between right and left and lower and upper stitches. All stitches on the right side will be into the lower bars, and all stitches on the left side will be into the upper bars.

Mattress Stitch On Garter Stitch                 

When you look closely at the garter stitch, you will see that there are smooth rows and bumpy rows created by knit stitches. For a neat finish, you will be sewing on the bumpy rows only.

You will use the same technique as described above by sewing through the upper bars (mountains) on one side and the lower bars (valleys) on the other.

Troubleshooting Mattress Stitch

• BUMPS - On occasion, you may miss one of the bars and effectively skip a row. This will cause a bump or a step in your seam. It is easily fixed by pulling out the mattress stitches until just below the bump, then re-sewing, making sure to pick up every bar without skipping any.
• MISMATCHED STRIPES - This shows up even more obviously than just a bump. Again, the solution is to pull out the mattress stitch to just below the mismatched part, then re-sew, making sure you include every bar.

How to Pull Mattress Stitch Out

Luckily mattress stitch is an easy stitch to unpick!

• Turn your work to the wrong side. You will see a small ridge where your seam has been made.
• Fold the ridge back and you will see a row of small straight stitches.
• Find the point where your mistake has happened, and slide the yarn needle under the stitch at that point.
• Pull the whole row of stitches out by pulling on that thread.
• Straighten out any gathers, re-thread the needle, and continue sewing.

Alternatives to Mattress Stitch

Whip Stitch

Whip stitch is a very quick and easy stitch, but it is not quite as invisible as a mattress stitch. To work it, place the right sides of the knitting together and secure your sewing yarn (or use a long tail from the cast on).

• Insert your needle into the right half of a stitch on the left piece, then the left half of a stitch on the right piece.
• Pull together, then lift yarn up and over the pieces of knit fabric.
• Continue in this manner all the way along the seam.

Back Stitch

Backstitch is also quick and easy, but it does create a wider seam at the back of the garment.

• Hold the right sides of the work together, wrong sides facing out.
• Secure the yarn, then bring the needle through both pieces of fabric.
• Take a small backward stitch through the fabric.
• Bring the needle through again a little in front of the first stitch.
• Take another backward stitch, inserting the needle where the previous stitch came through.

Slip Stitch Crochet

For those who really dislike sewing, but know how to crochet, this one is the answer! Here is how to slip stitch crochet:

• You can use it on both knit and crochet pieces.
• Place right sides together, wrong sides facing out.
• Insert a crochet hook through the edge stitch on both pieces, from front to back.
• Hold the yarn at the back.
• Use the hook to draw a loop through both pieces, to the side facing you.
• Then insert the hook again a little further down the seam. Draw another loop through.
• Pull the second loop through the first loop.
• Continue inserting, drawing up a loop, and pulling the loop through until the end of the seam.
• Draw the yarn through the final loop to secure, and weave in your ends.

Mattress Stitch - In Conclusion

I have included other seaming methods here, but the mattress stitch is by far the best method. It is very secure and really almost invisible. It is really worth giving it a try, as it is not at all difficult once you get the hang of it.

It is also most useful as a darning stitch on woven fabrics, so it’s definitely worth getting familiar with this one! Enjoy sewing up your creations! Don’t be one of those people who love knitting, but hate sewing, so their UFOs (unfinished objects) are all completely knitted, but not joined.