When I was researching how to join the squares for my Tetris Afghan, I knew I wanted a clearly visible joining that would outline the different Tetris blocks. However, I also wanted to make sure that the joined squares would lay flat.

I decided to use a crochet join. It uses only basic crochet techniques and creates a nice raised chain on top of the squares. It’s perfect for emphasizing the border between the squares, especially when using a contrasting color for the join.

The following steps show how to join afghan squares using this crochet technique:

1. Using your crochet hook, draw a loop through the bottom corner of Square 1.

2. Wrap the working yarn around the hook and draw a loop through the first loop.

3. Draw another loop through the bottom corner of Square 2.

4. Wrap the yarn around the hook and draw a third loop through the first two loops (Single Crochet).

5. Draw a loop through the next hole in Square 1 and perform another Single Crochet as in step 4.

6. Continue in this manner, staggering each new stitch.

7. When the top has been reached, make sure that you perform a Single Crochet in the top corner of each square. Then, leaving a long tail, cut the yarn and pull the end through the final loop.

Note: If the next two squares in line use the same color for joining as the active yarn, instead of cutting and finishing, you can continue to join the next two squares without break.

I find that the finished result looks best if the squares are first joined in strips vertically and then joined horizontally (or vice versa).