The popcorn stitch is named for its unique airy bubbled texture. It's similar to making bobbles on your knit fabric but there is a difference between the two. The bobble technique isn't meant as a full pattern, it's a way to add texture to your work. While the popcorn stitch is a repeatable pattern that you can use to knit anything from a sweater to a scarf. Popcorn stitches actually take two rows to complete, with the increase on one row and the decrease on the next.
Using the Popcorn Stitch
Popcorn can be worked in garter stitch or stockinette stitch, and the textured knots can be spread out however you like, whether evenly scattered over the whole fabric, used as stripes or worked randomly through a piece of knitting. It's great for baby blankets because the bobbles help retain heat and are fun to look at.
How to Work the Popcorn Stitch
Typically popcorn is made by making one stitch into four (by knitting, purling, knitting, and purling into the same stitch); the stitches are decreased by slipping the three new stitches, knitting the remaining stitch and passing the slipped stitches over the knit stitch one at a time.
Following is one common layout for the popcorn stitch, but you as long as you work at least two rows you can vary the number of "popcorns" to suit your taste.
Popcorn Stitch Pattern
Works on multiples of six plus five stitches.
Rows one through four: Knit.
Row five: Knit five, *(knit one, purl one, knit one, purl one) in the next stitch, knit five. Repeat from * across.
Row six: Knit five, *slip three, knit one, pass each slipped stitch separately over the last knit stitch, knit five. Repeat from * across.
Rows seven through 10: Knit.
Row 11: Knit eight, *(knit one, purl one, knit one, purl one) in the next stitch, knit five. Repeat from * across, ending knit three.
Row 12: Knit eight, *slip three, knit one, pass each slipped stitch separately over the last knit stitch, knit five. Repeat from * across, end knit three.
Repeat these rows for pattern. Note that even numbers are right side rows.