Crescent Bag Pattern: How to Sew a Crescent Sling Bag

Q: What fabric is best for a crescent bag?

A mid-weight outer such as cotton canvas, denim, cork fabric or vegan leather, lined with quilting cotton or poplin. Fusible fleece or foam stabilizer on the outer gives a more structured bag.

A crescent sling bag is a curved, zippered crossbody bag. To sew one, cut two crescent panels from the outer and two from the lining, sew the zipper between the two outer panels along the top edge, then sew a gusset strip around the curved edge. Make the lining the same way with a turning gap, add an adjustable webbing strap, join the outer and lining around the zipper and turn the bag through. The Sewzy Crescent Sling Bag comes in Mini, Everyday and Large, and takes about 2 hours at intermediate level.

TL;DR

Sizes: Mini 10 x 6 x 1¾ in, Everyday 13 x 7¼ x 2¼ in, Large 16 x 8¾ x 3 in.
Fabric: mid-weight canvas, denim, cork fabric or vegan leather outside; quilting cotton or poplin lining.
Hardware: a nylon coil zipper, 1 inch webbing, a 1 inch slider and two 1 inch D-rings for an adjustable strap.
Time: about 2 hours, intermediate. The curved gusset is the skill to take slowly.
Machine: a 90/14 needle; a walking foot helps on the curves.

The crescent sling bag this Sewzy pattern makes, view 2 — The Crescent Sling Bag from the Sewzy pattern. Photos are renders of the finished item, made from the pattern's shapes.

The crescent sling bag this Sewzy pattern makes, view 3 — The Crescent Sling Bag from the Sewzy pattern. Photos are renders of the finished item, made from the pattern's shapes.

Crescent bag sizes and fabric

Size	Finished (width x height x depth)	Outer fabric	Lining	Holds
Mini	10 x 6 x 1¾ in	1½ yd	⅜ yd	Phone, keys, cards
Everyday	13 x 7¼ x 2¼ in	1⅝ yd	½ yd	Phone, wallet, keys, a small pouch
Large	16 x 8¾ x 3 in	1⅝ yd	½ yd	The everyday kit plus a water bottle or a book

The zipper and webbing lengths for each size are in the pattern's size table. The ⅜ inch seam allowance is included; the fold edge at the center of the bag has none.

What fabric is best for a crescent bag?

A crescent bag looks best with some body, so pick a mid-weight outer: cotton canvas, denim, cork fabric or vegan leather. Line it with quilting cotton or poplin. For a more structured bag that holds its curve, fuse a layer of fusible fleece or foam stabilizer to the back of the outer panels. With directional prints, cut the panel so its straight top edge runs along the straight grain, which keeps the zipper line clean.

What you need

Outer fabric and lining, as in the table.
A nylon coil zipper, length from the size table.
1 inch webbing, a 1 inch slider and two 1 inch D-rings or rectangle rings. Skip the hardware for a fixed strap.
Thread, clips and a 90/14 needle.
Optional: fusible fleece or foam stabilizer for the outer.

How to sew a crescent sling bag, step by step

These are the nine steps of the Crescent Sling Bag pattern in short. If you have not printed a PDF pattern before, read how to print PDF sewing patterns first.

Cut. Print your size, check the 2 inch test square and tape the pages. Cut 2 crescent panels from the outer and 2 from the lining, with the fold at the bag's center. Cut the gusset, zipper top facing, strap and slip pocket by the measurements in the pattern.
Mark. Mark the top edge line, the gusset match notches and the strap tab marks on the outer panels, and the pocket lines on the lining panels.
Sew the lining pocket. Press under the edges of the pocket, hem the top and edgestitch it to one lining panel along the sides and bottom.
Install the zipper. Sandwich the zipper tape between a zipper top facing strip and the top edge of one outer panel, right sides together, and stitch. Press the facing away from the zipper and topstitch. Repeat on the other side with the second outer panel.
Gusset the outer bag. Pin the outer gusset around the curved edge, matching the notches, and ease the fabric evenly with no tucks. Stitch all the way round. The zipper ends meet the gusset ends at the top corners.
Gusset the lining. Sew the lining the same way, leaving a 4 inch gap in the gusset seam for turning.
Make the strap. Thread the webbing through the slider and D-rings, stitch the ends and box-stitch the tabs at the strap marks. For a fixed strap, stitch plain webbing straight to the tabs.
Join the outer and lining. Slip the outer bag into the lining, right sides together, with the zipper open and the strap tabs between the layers. Stitch around the zipper opening.
Turn and finish. Turn the bag right side out through the zipper and the lining gap, then close the gap by hand. Push the lining in, press and topstitch close to the zipper on both sides.

Tips for the curved gusset

Ease, do not stretch. Pin the gusset at the notches and the two ends first, then spread the fullness evenly between them.
Use a walking foot if you have one, so the curved seam and the zipper feed evenly.
Clip into the seam allowance on the tightest part of the curve before turning, without cutting the stitches.
New to zippers? Practice on a Zipper Pouch first; how to insert a zipper covers the basics.

Crossbody or waist bag

The same panel and gusset make a crossbody sling or a waist bag; only the strap length and hardware change, and the pattern notes how. For a softer, quicker bag with no zipper, see the hobo bag guide, and for a padded look, how to sew a puffer bag.

A handmade gift

A Mini crescent bag in cork fabric or a Christmas canvas makes a stylish gift for a teenager or a friend who likes to travel light. The pattern, with printable pieces for all three sizes and a photo for each step, is a Premium pattern in the Sewzy app. More bag ideas are in how to sew a lined tote bag.