Did you know there’s an invisible way to seam ribbing stitch in knitting? Learn how to get a perfect finish for ribbed cuffs, necklines and more in this step by step mattress stitch tutorial.
Note: I have a separate mattress stitch for stockinette guide here
Table of Contents
Mattress Stitch for Rib Video Tutorial
See exactly how to seam ribbing with mattress stitch in this 5 minute video:
There’s also step by step written instructions with close-up pictures below if you prefer:
Why Mattress Stitching Rib is Invisible
Ribbing has clear knit stitch columns. If you stretch your ribbing out, you see purl stitch columns in between each knit stitch.
To seam rib with mattress stitch, you want a knit stitch on both sides of the seam. So you seam into purl stitches on both sides and this disappears in the middle.
This invisible seam looks like the rest of your rib for a super neat finish.
Note: I’m using a contrasting colour in the pictures and video in this guide to make the demo clearer and to show you how invisible a mattress stitch ribbing seam is.
Most Important: Where to Put your Needle
Just like with mattress stitch for stockinette, the key is knowing exactly where to put your needle.
The golden rule with mattress stitching rib is to work into the first purl stitch on each side.
So if you have an odd number of rib stitches, starting and ending with a knit stitch, you work 1 stitch in on both sides, just like mattress stitching stockinette.
But if you have an even number of rib stitches, that means the first stitch is a knit stitch on one side, but a purl stitch on the other.
You always seam into a purl stitch on both sides. So you still work 1 stitch in on the side that starts with a knit stitch. But you work in the very 1st stitch on the other side, because it’s a purl column.
Purl Stitch: u and n Shapes
If you look at any purl stitch column, it’s made up of u shapes, or smiles if you prefer. And then beside these there are n shapes, or frowns.
So to get an invisible seam, we’ll seam through the u shapes on 1 side and the n shapes on the other.
It doesn’t matter which side is your u side and n side.
Seam Every Row
When mattress stitching stockinette, you seam 2 rows at a time by going under 2 bars at a time on each side. But with ribbing, you seam every row instead.
Now the side that starts with a purl stitch only looks like it has half the number of rows at first glance.
So my top tip is to carefully count the rows on both sides first.
If you stretch out the first purl stitch column and look closely, you realise there are more rows hiding there.
Putting your needle through all the n shapes or u shapes makes them easy to count.
You may also find it easier to get at the n shapes on 1 side than the other.
How to do Mattress Stitch for Ribbing
Step 1: Go Under the 1st U Shape on 1 Side
Note: If you are continuing on from seaming stockinette, e.g. down to the cuff of a hat or sleeve, start on the opposite side to the last stitch as usual.
If you picked the first side as your u side, go through the first u shape you see in the 1st purl stitch on that side. Otherwise go through the first n shape and do a u in step 2 instead.
If you’re continuing on from a stockinette seam, it’s easy to see the first row of rib, because you can see the little u bumps above the stockinette all along it.
Put your needle through the first u shape and pull through loosely as usual.
Step 2: Go Under the 1st n Shape on the Other Side
Now on the other side, look for the n shape in the 1st purl stitch in the 1st row of rib.
Put your needle through the n and pull through loosely.
Step 3: Repeat Steps 1 and 2 Several Times
Now back to the 1st side, and go through the next u shape just above where you did the last stitch and pull through.
And back to the other side. It’s harder to make out each individual row in the edge purl stitch. So stretch it out a bit to make sure you’re not skipping a row.
Then put your needle through the next n shape and pull through loosely.
Then you just repeat the same steps for every rib row. Just make sure you stick to 1 shape on each side. In the video demo above I’m seaming through u shape stitches on the right and n shapes on the left.
If you have an even number of rib stitches, which means you’re seaming into an edge stitch on one side, take time to stretch out that stitch so you don’t miss any rows.
Step 4: Pull to Make your Seam Disappear
Once you reach the end of your ribbing (or just the 1st chunk of rib if it’s a longer piece rather than just a cuff), it’s time for the magic. Give your seam a big pull and watch it disappear.
When you pull apart the seam, you see n shapes beside u shapes, just like any other purl stitch in your rib.
And because you’ll be using matching yarn instead of a contrast colour, it really will look invisible.
I hope this guide helps you easily seam all your ribbing to get neat necklines, crisp cuffs & more. Got any questions? Just comment below and I’ll try my best to help.