Materials
Medium-weight cotton yarn
Crochet hook suitable for the yarn
Scissors
Yarn needle
Measuring tape
Abbreviations
ch = chain
sc = single crochet
dc = double crochet
sl st = slip stitch
st = stitch
sk = skip
Pattern
Start with a foundation chain in the desired width.
Row 1: Work single crochet across the foundation chain. Chain 1 and turn.
Row 2: Work single crochet across the entire row, keeping the stitches even.
Row 3: Begin the decorative shell row. Work the required stitches into the same stitch to form a fan-shaped shell, then skip the appropriate stitches and repeat the shell across the row.
Row 4: Work a row of single crochet across the top of the previous shells, keeping the edge straight.
Repeat the shell pattern and the separating rows until the piece reaches the desired length.
For each shell, create several double crochets or tall stitches in the same stitch to form a rounded fan. Secure each shell with a connecting stitch before beginning the next one.
Keep the tension consistent so that the scallops remain evenly spaced and the fabric lies flat.
Edging
Work a final row of single crochet around the entire piece.
At the corners, add extra stitches if necessary to prevent curling.
Finish with a slip stitch, cut the yarn, and weave in all loose ends.
Finishing
Gently stretch and shape the finished crochet piece.
Block it lightly to define the scalloped shells and create a neat rectangular shape.
The finished design has a textured base with repeated raised scallop motifs arranged in horizontal decorative rows.