In this video I’m showing you how I do the mattress stitch for the Birthstone Blanket, step-by-step, so you can get those seams looking clean and tidy. If you’ve been crocheting your squares (or panels) for the crochet-along and you’re ready to start putting it all together, this is the join I reach for when I want the seam to lay nice and flat and look polished. I walk you through where to place your needle, how to line up your stitches so the edges match, and what to watch for so you don’t pull too tight or leave gaps. My biggest takeaway is to take your time, keep checking your alignment as you go, and let the stitch do the work—mattress stitch is one of those techniques that looks fancy, but once you get the rhythm, it’s super doable. Grab your yarn needle, get comfy, and let’s seam this blanket up together.