Clamshell quilt block
One shell shape in rows, each row tucked half a shell over from the one above. The curves are usually turned under and appliquéd row by row.
Cutting by template size
| Shell width | Strip width | Pieces per strip | Pieces for a throw |
|---|---|---|---|
| 2" | 2½" | 16 | 2226 |
| 3" | 3½" | 12 | 1004 |
| 4" | 4½" | 9 | 573 |
| 5" | 5½" | 7 | 375 |
Strips are cut across 42" fabric with ¼" seam allowances. Counts include the part pieces that get trimmed at the edges.
Fabric for every bed size, 3" shell width
| Size | Quilt top | Pieces | First fabric | Second fabric | Third fabric |
|---|---|---|---|---|---|
| Crib | 45" × 60" | 635 | 2 yd (212) | 2 yd (212) | 2 yd (211) |
| Throw | 60" × 72" | 1004 | 3 yd (334) | 3 yd (335) | 3 yd (335) |
| Twin | 70" × 90" | 1464 | 4½ yd (488) | 4½ yd (488) | 4½ yd (488) |
| Full | 84" × 96" | 1852 | 5¾ yd (617) | 5¾ yd (618) | 5¾ yd (617) |
| Queen | 90" × 108" | 2226 | 6¾ yd (742) | 6¾ yd (742) | 6¾ yd (742) |
| King | 108" × 108" | 2664 | 8 yd (888) | 8 yd (888) | 8 yd (888) |
Yardage includes 10% extra, rounded up to the next ¼ yard. Add borders, backing and binding as for any quilt of that size.
Templates for the 3" shell width
Print this page at 100% (actual size) and check that the square below measures 1". The solid line is the sewing line and the dashed line is the cutting line, ¼" outside it.
Design a quilt with this block
Quiltspiration draws it in your own fabric and gives the cut list for any size.
