The Mattress Stitch is a finishing technique for vertical seaming along selvages. It creates an invisible join between pieces worked in stockinette stitch or ribbing, perfect for so many things, such as sewing the front and back of a sweater together. For our Mattress Stitch Tutorial, we have used a different yarn in a contrasting color, but typically you would use the same yarn as your knit pieces.

NOTE: If you need to seam together cast-on and bind-off edges, be sure to visit our Seaming Stockinette Stitch Tutorial!

VIDEO TUTORIAL

Click To See Video Transcript

Hey guys, this is Laura from Purl Soho and I’m going to show you how to do the Mattress Stitch. The Mattress Stitch is a great technique for seeming together vertical edges. You can see here I have two swatches of stockinette-stitch fabric worked up for you. I have the right sides facing me. That’s because I want my seam on the wrong side of the fabric, and the goal here is to make it look like these two pieces of fabric are one big piece of fabric. 

Before we get started though, let’s take a quick look at this, our stitches. So if you gently pull on your fabric, you can see these horizontal bars that reach between the rows of knit stitches. What we want to do is pick up those bars using a tapestry needle along both edges of our swatch to pull them together. I’m going to show you how you do that. 

So take your threaded tapestry needle. I’m using a contrast color yarn just for demonstration purposes here today. But take your tapestry needle come from the back or the wrong side of your fabric between the two most outer rows of stockinette stitches. So you know how stockinette stitch loves to curl. So make sure, here’s one row and here’s our second row. We want to come through from the back between those two rows of stitches. Oops, getting a little tangled up with our tails. There we go. Okay, now we want to find that same point on our other swatch, but this time we’re going to come from the front of the fabric between these two rows and push the needle in the direction you’re working and you’ll just pick that bar right up. You see that? 

All right. Okay, so now what you want to do is take your tapestry needle and put it in the exact point where the working yarn last left this swatch. So push it right down where your working yarn is coming out and push it in the direction you’re working, and that bar should just slip right onto your needle. All right, and let’s come back over to this. Do the same thing. Put your tapestry needle where you last came out. Gently push it in the direction you’re working. There you go. The bar will slip right on. 

Now I’m working in a worsted-weight fabric, and so I’m picking up every bar as I travel along my vertical edge. If you’re working in a fingering weight or a lace weight, anything really smaller than dk, what you’re going to want to do is probably pick up two bars at once, and I’m going to show you how to do that. 

So the main principle is the same. You take the tip of your tapestry needle, you place it where your working yarn last left this swatch, and instead of picking up just one bar, you pick up two. Let’s do it one more time. There we go. Two bars. All right. 

So you can see here I’m keeping my stitches pretty loose, but you can go back and tighten them. Don’t work too far without tightening them up. No more than an inch or two before you adjust your working yarn to see how your seam is coming along. So let’s do that right now. So you take your working yarn and you just gently tug it, and it really just zips these two fabrics together. Do you see how these rows of knits stitches have just come together in this seamless fashion? Let me show you the wrong side so you can see this very professional looking seam you’ve created, or we’ve started creating, I guess. Mattress Stitch is by far my favorite finishing technique. It’s so effective, incredibly seamless, and super simple to do.

STEP-BY-STEP TUTORIAL

You will be sewing two knit pieces together by grabbing a strand of yarn from each edge, alternating back and forth, working vertically along the edges. The strand of yarn you grab is a horizontal bar that runs between the knit stitches (or “V”s). If you gently tug on the right and left edge of your knit piece, you can see these horizontal bars (or “ladder”) between the Vs. Picking up a bar from each side draws the edges together, making it appear as though it is one knit piece.

To begin, align the two pieces you wish to seam. Bring your threaded tapestry needle from the back of your work to the front at the location where you wish your seam to start.

Mattress Stitch | Purl Soho

Next, draw the needle under the bar between the two most outer Vs of the second knit piece, right across your entry of the first edge. Beware of the outermost column of knit stitches; it tends to curl to the back. The farther in from the edge that you work, the bulkier the seam will be.

Mattress Stitch | Purl Soho

Take the tapestry needle back to the first piece and pick up the bar just above your initial entry point.

Now, take the needle back to the second piece and pick up the bar above the last one your picked up on this side.

NOTE: Depending on the gauge or density of the fabrics, sometimes it is just as effective to pick up every other bar, rather than ever bar. It is a personal choice.

Continue working vertically along the two edges, drawing the tapestry needle under each bar of each piece.

Above you can see the many red stitches connecting the two columns of Vs. The goal is to bring those Vs together.

Mattress Stitch | Purl Soho

Just as with knitting, the more even you can keep your tension, the better. An even tension will prevent pulling and puckering along the seam.

Mattress Stitch | Purl Soho

To close the seam, gently pull the length of yarn from either the top or the bottom. If you are working a long seam, it is best to sew a few inches, then pull to close, again sew a few inches and pull, continuing in this fashion to the end of the seam, being careful to maintain a consistent tension throughout.

Mattress Stitch | Purl Soho

It’s like magic.

Mattress Stitch | Purl Soho

If you turn your work over so the wrong side is facing, you’ll see the seam.

Looking for more inspiration? Explore all of our free knitting patterns and knitting tutorials, buy one of our many knitting kits and yarn bundles, and shop for beautiful yarn. We have over 35 gorgeous natural fiber yarns in 100’s of magnificent colors, designed to bring integrity, beauty, and joy to your next knitting project and only available at Purl Soho!