As you might know, the shell stitch is available in many varieties. I was looking for a dense, compact shell to compliment the blanket. And I think I found it!
Join your colour with a ss in the first stitch. Crochet four ch, that count as dc and ch (photo 1). Crochet two dc in the same stitch (photo 2). This is your first half shell. Skip four stitches, and crochet two dc, two ch and two dc in the next stitch (photo 3) This is a full shell. Repeat the skipping of four stitches and working a shell in the next stitch until the end of the row. In the last stitch, work a half shell by making two dc, a ch and another dc (photo 4). Turn your blanket.
Crochet a ch, and work a sc in the chain space of the half shell (photo 5). Crocheting in the space between the shells of the previous round, make a shell consisting of two dc, two ch and two dc. Crochet another sc in the chain space of the next shell (photo 6). Continue like this until the end of the row (photo 7). Cut your yarn and turn your blanket.
Join a new colour with a ss in the chain space of the shell two rows back, over the sc of the previous row (photo 8). Crochet four ch (count as dc and ch), crochet two dc in the same chain space (photo 9). Work a sc in the chain space of the next shell (photo 10). Now crochet a shell by working two dc, two ch and two dc in the chain space two rows below, over the sc of the previous row, and then make a sc in the next chain space (photo 11). Repeat the shells and the sc in between until the end of the row, ending with two dc, a ch and a dc in the final chain space (photo 12).
Repeat the second row just like two rows back: Start with a sc, crochet shells in the chain space two rows back. This is how you crochet dense shells!