Alternating double crochet and slip stitch are used to form the texture portions of this pattern. I've worked out three different starting chain lengths for a narrow wristband (or exercise sweatband), wristwarmer and a longer wrist/arm warmer.
Abbreviations: ch = chain, chs = chains, ea = each, dc = double crochet, sc = single crochet, sl st = slip stitch, sp = space, st = stitch, st ch = starting chain
How To Slip Stitch: Insert the crochet hook in the next stitch to be worked, wrap the yarn over the hook, pull the yarn through the stitch to be worked and the loop already on the hook, all at the same time.
Materials: any worsted weight yarn, acrylic or other fibers (from 1/3 oz. to about 1 oz. for the various sizes), US size H hook. For wearing in hot weather or for use as exercise sweatbands, cotton yarn is recommended.
Pattern Notes: When you are working into the dc stitches, remember that the short height of the slip stitch next to each double crochet has pulled that dc downward so it doesn't look like a usual double crochet. Still, it shows as slightly taller than the slip stitches and once you are used to the look of the crunched down double crochet, you will be able to determine which are double crochet and which are slip stitches across the row. You will insert the hook under the top loop of each double crochet, as usual, when working into the dc stitches.
If you want additional stretch for the wristband, you could work every row in the back loops only.
Sizes: st ch of 9 chains = about 2 1/4 inches long, st ch of 17 chains = about 4 inches
long, st ch of 31 chs = about 7 1/2 inches long
The width is determined by the number of rows you crochet to get the fit you need.
You will turn at the end of each row.
Starting Chain: ch 9, (17 or 31).
Row 1: sc in second ch from hook, sc in ea ch across. (making 8, 16 or 30 sc in the row)
Row 2: ch 1, sc in back loop only of first sc, sc in back loop only of ea sc across the row. (8, 16 or 30 sc)
Row 3: ch 3 (counts as first dc), being sure to skip the sc that is at the base of the ch-3 just made, (sl st in next sc, dc in next sc) as many times as needed to go across the row, until only one sc remains, then sl st in that last sc.
Row 4: ch 3 (counts as first dc), sl st in next dc, (dc in next sl st, sl st in next dc) as many times as needed to go across the row until only one sl st and the ch-3 at the end of the row remain, then dc in next sl st, sl st in the 3rd ch of the ch-3 at the end of the row.
Row 5: ch 3 (counts as first dc), being sure to skip the sl st that is at the base of the ch-3 just made, (sl st in next dc, dc in next sl st) as many times as needed to go across the row, until only the ch-3 at the end of the row remains, then sl st in 3rd ch of that ch-3.
Row 6: ch 1 (to turn), sc in the first sl st, (sc in next dc, sc in next sl st) as many times as needed to go across the row, until only the ch-3 at the end of the row remains, sc in the 3rd ch of that ch-3. (8, 16 or 30 sc in the row)
Rows 7 - 10: ch 1, sc in back loop only of first sc, sc in back loop only of ea sc across the row.
Rows 11 - 18: Repeat Rows 3 - 10.
Additional Rows: Repeat Rows 3 - 10, stopping when the width of the wristband is the right width to fit the wrist of the person who will be wearing it, with enough stretch to comfortably fit over the hand while putting it on.
Joining: Fold the piece with the right sides held together, with the edge of the last row that you made lined up with the edge of the starting chain. Join with slip stitch, working through the corresponding stitches of both edges at the same time, to join the edges. If you prefer, you could sew together with a long yarn strand, using a large-eye sewing needle. End off, leaving a strand for weaving in. Weave in the ends, to secure. Turn right side out.