Materials
Medium-weight cotton yarn
Crochet hook suitable for your yarn
Scissors
Tapestry needle
Abbreviations
ch = chain
sc = single crochet
dc = double crochet
sl st = slip stitch
st = stitch
sk = skip
shell = 5 dc worked into the same stitch
Foundation Row
Chain a multiple of 6 + 1.
Row 1: Work 1 sc into the second chain from the hook and 1 sc into each chain across. Turn.
Row 2
Chain 1. Work 1 sc in the first stitch.
Skip 2 stitches, then work 5 dc into the next stitch to create the first shell.
Skip 2 stitches, work 1 sc into the next stitch.
Repeat across: skip 2 stitches, 5 dc in the next stitch, skip 2 stitches, 1 sc in the next stitch.
Turn.
Row 3
Chain 3.
Work 4 dc around the first shell area, forming a shell between the previous row’s shells.
Work 1 sc into the center/top of the next shell.
Repeat the shell and sc sequence across the row.
Finish with a dc in the final stitch. Turn.
Row 4
Chain 1.
Work sc stitches across the row, placing the sc stitches into the spaces between the shells to create a firm base for the next decorative row.
Turn.
Row 5 – Scalloped Shell Row
Chain 1.
Work 1 sc in the first stitch.
Skip 2 stitches and work 5 dc into the next stitch.
Skip 2 stitches and work 1 sc into the next stitch.
Continue this sequence across the entire row.
The 5-dc groups create the large rounded fan/scallop shapes visible in the sample.
Repeat
Repeat Rows 3–5 until the piece reaches your desired height.
For the pictured fabric, keep the shell rows aligned vertically so the scallops form neat repeating bands.
Finishing Edge
Work 1 row of sc evenly around the entire piece.
At each corner, work 3 sc into the corner stitch to keep the edge flat.
Fasten off, cut the yarn, and weave in all ends with a tapestry needle.
Final Result
This pattern creates a dense crochet fabric with repeated raised fan/shell motifs and rounded scalloped edges, similar to the stitch shown in the photo.