This is a pattern created by combining the cast on of https://www.ravelry.com/patterns/library/scintillation, with the design of https://www.ravelry.com/patterns/library/christmas-sand-d..., mostly because I’ve been knitting scintillation for a couple of months, and I like how it comes together, plus I’m horrible at mattress stitch.

Materials:
-- 20 yards DK yarn
-- Partial skein of darker color for the design once finished
-- One set – US size 0, 2.00 mm double-pointed needles (dpns) – This can be knit all on the dpns, but I find doing a magic loop cast on to the circulars is easier for me
-- Two – US size 0, 2.00 mm circular needles – This can be knit all on the circulars, but the decreases toward the end of each side would be more difficult (at least for me)
-- Stuffing (polyfill or whatever you like) – you will use a scant amount if any as sand dollars are mostly flat
-- Embroidery needle for weaving in ends and finishing design

Gauge:
Not horribly important, but you need to know that should you work with thicker yarn or larger needles, you would need more yardage to start. That being said, with this weight, and these needles in stockinette stitch, gauge is 29 stitches (sts) and 40 rows = 4 inches x 4 inches (10.2 cm x 10.2 cm)

Finished size:
3 inches (7.6 cm)