Sewing with chambray: the easy denim look

Chambray is a plain-weave cotton with a colored warp, usually indigo blue, and a white weft, which gives it the look of light denim at 100 to 200 gsm (3 to 6 oz/yd²) with the softness of a shirting. Sew it like any medium-weight cotton: an 80/12 universal needle (90/14 above 180 gsm), all-purpose polyester thread, a 2.5 mm stitch, and flat-felled or serged seams because it frays. Pre-wash it, since it shrinks and the indigo can bleed, and press on the cotton setting. It is one of the easiest fabrics for a first shirt, dress or pair of summer trousers.

Quick reference for sewing chambray

What is chambray and how is it different from denim?

Both fabrics pair a dyed warp with a white weft, which is why they share that heathered blue surface and fade in the same way. The difference is the weave. Denim is a twill, with the warp floating over two or three wefts to form diagonal lines; that makes it dense, stiff and lighter on the wrong side. Chambray is a plain weave, one over one under, so it is thinner, softer, drapes more and looks nearly the same on both sides. The flat weave also makes it cooler to wear, which is why chambray turns up as shirts and summer dresses rather than jeans.

Weights vary more than the name suggests. Shirting chambray sits around 100 to 130 gsm (3 to 4 oz/yd²); dress and trouser weights run 140 to 200 gsm (4 to 6 oz/yd²). Cotton-linen chambray has a looser, more textured weave and creases more; Tencel chambray drapes like a fluid viscose and sews like one too. Chambray is also made in black, grey, pink and in fine stripes and checks, and the yarn-dyed stripes are worth matching at the seams.

How do you prepare and cut chambray?

Wash chambray before cutting, on its own the first time, because indigo warp yarns release dye into the water and onto anything pale. Wash and dry it the way the finished garment will be treated: a cotton chambray shrinks 3 to 5 %, most of it in the length, and a tumble-dried fabric shrinks more than a line-dried one. Press it dry on the cotton setting and straighten the grain.

Chambray is stable and does not slip, so it cuts cleanly on the fold with shears or a rotary cutter. It is not directional, but a cross-dyed fabric can show a slight difference in shade when pieces are turned, so lay every piece in the same direction to be safe. Mark with white chalk, which shows on blue and brushes off, and check the right side by looking for the side where the colored warp is slightly more visible; on many chambrays either side can be used, so decide and mark it. Striped chambray follows the rules in matching plaids and stripes.

How do you sew chambray?

An 80/12 universal needle, polyester thread and a 2.5 mm stitch are all a shirting chambray needs; the fabric feeds evenly, pins well and presses crisp, so seams stay where you put them. Heavier chambray takes a 90/14 and, at collars, cuffs and waistbands, benefits from grading the seam allowances to cut bulk.

The seam finish is where chambray turns from fine to professional. A flat-felled seam encloses the raw edges and adds a second line of topstitching, which is what gives a chambray shirt or a pair of trousers the look of ready-to-wear: sew the seam at 1.5 cm, trim one allowance to 6 mm (1/4 in), fold the other over it and edgestitch it down. On a light shirting, a French seam is quicker on long straight seams, and a serger handles everything else. The fabric frays steadily, so finish edges before the pieces are handled much.

Topstitching is traditional on chambray: a 3 mm stitch in gold or tan thread echoes jeans, and tone-on-tone thread gives a quieter finish. Use a topstitch needle, which has a larger eye for the thicker thread, keep all-purpose thread in the bobbin, and topstitch 6 mm from the edge with the edge-stitching foot as a guide. Buttonholes sew cleanly with a light fusible interfacing behind the placket; test one on a scrap with the same layers.

Tip: Chambray shows every unpicked stitch as a row of holes. Baste anything you are unsure of with a 4 mm stitch first, and steam the holes closed if you have to unpick.

How do you press chambray?

Press on the cotton setting with plenty of steam. Press each seam flat as sewn, then open, then into its final position; a flat-felled seam is pressed open, then with the wide allowance folded over the trimmed one, before it is stitched. Dark chambray can shine under a hot iron, so use a press cloth on the right side. Creases set well, which makes pleats and crisp hems easy, and topstitching looks best when the seam has been pressed before the stitching goes in rather than after.

How do you hem chambray?

A topstitched double-fold hem suits the fabric: press 1 cm (3/8 in) to the wrong side, then 2 cm (3/4 in), and stitch close to the inner fold at 3 mm. On a shirt with a curved hem, make both folds 6 mm (1/4 in) and sew a guide line at 6 mm first so the curve turns evenly. Trousers and shorts take a 3 cm (1 1/4 in) double-fold hem in topstitching thread, or a blind hem by machine when you want nothing to show on the outside. Aprons and square corners are neatest with a mitered corner.

What to sew with chambray

• A woven top with a button front is the classic chambray shirt: shirting weight, flat-felled side seams, gold topstitching if you like.
• A shift dress in dress-weight chambray wears from spring to autumn and needs no lining.
• Pull-on shorts or trousers in a 160 to 200 gsm chambray give the look of light denim with an elastic waist and a soft hand.
• An apron in a heavy chambray with contrasting topstitching takes hard wear and improves with washing.

Chambray is usually sold 140 to 150 cm (55 to 60 in) wide; Sewly's sewing guide gives fabric quantities for 110, 140 and 150 cm (45, 55 and 60 in) widths, so pick the one that matches the bolt. Buy 10 % more than the pattern asks for to cover shrinkage, and wash it as soon as it comes home.