Mattress stitch

To join crochet parts, you can either crochet them together, for example with the "zipper joining method" or you can sew them together with a needle.

My favorite stitch for sewing is the mattress stitch. Especially when I work with slip stitch crochet it is great. Here are my two favourite ways to do it.

Version 1:  Picture above. I have used a piece of yarn in a contrasting colour for better clarity. The needle goes down through one loop on the right side, then up through a loop on the left side, down through the next loop on the left side, up through the loop on the right side where it came from before, down through the next loop on the right side, up through the loop on the left where you have previously gone down, And so on. Every loop is used for one "up" and one "down".
It is probably easier to understand by the picture.

Result below.

Version 2: The needle goes down through a loop on the left side, then up through the next loop on the same side, down through the loop on the right side where it came from before, up through the next loop on the right side, down through the loop on the left side where it came from before, up through the next loop on the left, and so on.
As with the first version, every loop is used for one "up" and one "down".
Result  below.

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