If you have two pieces of crochet to sew together, use the Mattress Stitch! A favorite when joining crocheted granny squares or crocheted clothing.
Mattress Stitch Join Tutorial - MyCrochetory
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How to Crochet: Mattress Stitch Seaming
How to Join Crochet with the Mattress Stitch [+ Video Tutorial]
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A mattress stitch tutorial - Little Cotton Rabbits
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