luxurious baby blanket

I started my first baby blanket last week! I bought this gorgeous yarn to make a "baby sack with hood," but quickly realized that a better (i.e., more likely to be used more often), item to make with such a luxurious yarn (Debbie Bliss Alpaca Silk) would be a blanket. I briefly considered making a sweater with this yarn, but decided against it because I was worried about the yarn stretching and growing.

Before starting, I knitted a very small swatch using 10 yards of the yarn. After crunching some numbers based on this swatch, I decided how many stitches to cast on. I'm aiming for the final result to be an approximately 30 inch x 30 inch blanket. In reality, as long as I can use up all 13 balls of this yarn and the length and width are within 10 inches of one another, I'll be happy!

Cast on 130 stitches. Work 5 rows in garter stitch. While maintaining 5 edge stitches on each side in garter stitch, start basketweave stitch (k5, p5) on 6th row. Work in this pattern for 5 rows before switching (k on the ps, p on the ks).