How to Crochet a Flat Slip Stitch Seam

Flat slip stitch seams in crochet

A flat slip stitch seam is one of many ways to join together crochet motifs into larger projects. I recently used this technique to join squares together into a blanket and loved the finished look! This seaming technique does not leave a ridge on either side of your crochet project – it is completely flat!

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What materials will I need to crochet a flat slip stitch seam?

For starters, you will need some finished crochet motifs to seam together. You could also potentially use this technique with other materials besides crochet pieces, but they will either need to have crochet stitches around their edges, or at the very least, holes around the edges to work into. If you try something unique and inventive with this technique, I’d love to see it!

I joined together the squares of my Fall Feels Throw Blanket. You can find all the written patterns for the squares in this post.

Next, you will need yarn that is the same weight as the squares or motifs you are joining. I used worsted weight Cascade Yarns Pacific, which you can purchase or order at your local yarn shop (LYS).

You will also need a crochet hook. I used a Furls Streamline Resin crochet hook with a nice ergonomic handle, which you can see here.

Flat slip stitch join written instructions

While joining, always insert hook through chs and sts from front to back.

The chains of corner ch sps will be joined along with the side to which they are closest. Each side has 25 sts, but the joining for each side will include 27 sl sts, because you will include one ch at each end from the corner ch sps.

Place first square of second column on a flat surface in front of you with RS up. Place first square of first column also RS up in front of you above the first square so that the line between them runs horizontally across your flat surface. Make a slip knot in yarn and place it on hook.

Insert hook through back loop of first ch of first corner ch sp of top square, insert hook through back loop of second ch of first corner ch sp of bottom square, yo and pull through both chs and loop on hook. As you continue, keep working yarn below squares and hook so that when you yarn over your hook you are pulling the working yarn from underneath your join.

*Insert hook through back loop of next st of bottom square, insert hook through back loop of next st of top square, yo, pull through both sts and loop on hook, insert hook through back loop of next st of top square, insert hook through back loop of next st of bottom square, yo, pull through both sts, repeat from * across in every st and corner ch, working each corner ch with the side to which it is closest.

After you join one set of squares, ch 1, and continue right on to join the next set of squares in order in the two columns. When you have completed joining all the squares in those two columns, fasten off. Then join in order all the squares of the next column. Once you have joined all of the columns of squares, turn your blanket and join all of the rows together in the same manner.

Flat slip stitch seam video

Square placement for the Fall Feels Throw

You can place your squares however you like them!

Your square placement can be random, planned, scattered, or patterned. The diagram and key below show how I placed my squares.

Visit the Fall Feels Throw Blanket post to get the patterns for each crochet square and the edging as well.

This finished up this flat slip stitch seam crochet tutorial. Have you tried it with some of your own crochet squares or motifs? Did you enjoy working the seam? I found the rhythm of it very enjoyable. What is your favorite method for joining crochet squares?

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Happy crocheting!

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