Viscose (also sold as rayon) is easy to love and tricky to sew: it drapes beautifully, but it shifts while you cut, stretches out on curves and shrinks in the wash. Pre-wash it gently the way you will wash the garment, let it rest flat, cut it with weights and a rotary cutter (single layer for the slippery types), staystitch curves straight away, sew with a fine 70/10 or 80/12 microtex needle and a 2–2.5 mm stitch, and press on a medium setting with a pressing cloth.
What is viscose, and why is it tricky to sew?
Viscose is a regenerated cellulose fiber: wood pulp dissolved and spun into filaments. "Rayon" is the generic name used in the US; viscose is its most common type, and modal and lyocell are close relatives made by different processes. Viscose breathes like cotton and drapes like silk, which is why it is everywhere in summer dresses.
Its quirks come from the same fiber. It is weaker when wet, so it can grow and distort in the wash. It shrinks, sometimes more along the length than across it. Its smooth fibers slide over each other, so cut pieces shift and curves stretch when handled. None of this is a reason to avoid it; it only asks for a slower start.
| Viscose type | Weight | Character | Good for |
|---|---|---|---|
| Challis | 100–130 GSM (3–3.8 oz/yd²) | Soft, fluid, often printed | Skirts, blouses, summer dresses |
| Crepe | 110–160 GSM (3.2–4.7 oz/yd²) | Pebbly texture, springy, very fluid | Dresses, wrap skirts, slip dresses |
| Twill | 140–190 GSM (4.1–5.6 oz/yd²) | Heavier, diagonal weave, less slippery | Trousers, shift dresses |
| Poplin | 110–140 GSM (3.2–4.1 oz/yd²) | Smoother and crisper | Tops, shirts |
| Viscose-linen | 150–200 GSM (4.4–5.9 oz/yd²) | Linen look with more drape | Trousers, dresses, kimono jackets |
For your first viscose project, choose twill or viscose-linen: they behave much like cotton and still give you that fluid fall.
How do you pre-wash viscose?
Wash it the way you intend to wash the finished garment, usually a gentle cycle at 30 °C (86 °F) or by hand. Do not wring it: roll it in a towel to remove water, then dry it flat or over a line, supported along its length. Expect several percent of shrinkage, more on crepes, and some loss of the crisp finish it had on the bolt.
Zigzag the cut ends first, and press the fabric on a medium setting once it is dry. If you plan to tumble-dry the garment, tumble-dry the fabric too, but many sewists prefer to line-dry viscose for its whole life: it keeps its shape and color longer.
How do you cut viscose without it moving?
Cutting is where most viscose projects go wrong. These habits help:
- Let it settle. Lay the fabric on the table and leave it for 15–30 minutes so it relaxes. Do not let any part hang off the edge; its weight drags the grain out of line.
- Straighten the grain. Line one selvedge up with the table edge or the grid of a cutting mat, then smooth the fabric outward with your palms, never by pulling.
- Cut single layer for slippery challis and crepe, flipping the pattern piece over to cut the second of a pair. Cut double layer only on stable twills.
- Use weights and a rotary cutter. Pins and scissors lift the fabric. If it still slides, lay it on a sheet of tissue or pattern paper and cut through both.
- Mark gently with tailor's chalk or a washable pen, and cut notches outward rather than snipping into the seam allowance.
The guide to laying out and cutting fabric on grain explains how to check the grain on every piece.
Which needle, thread and stitch settings work best?
Use a microtex (sharp) needle, 70/10 for challis and crepe and 80/12 for twill and viscose-linen. A sharp point slips between the fine fibers instead of pushing them aside, which prevents pulled threads and puckers. Use all-purpose polyester thread and a stitch length of 2–2.5 mm (10–12 stitches per inch).
Hold both threads behind the foot for the first few stitches so the fabric is not pushed into the needle plate, or start on a small scrap and sew straight onto your piece. If the layers creep apart, reduce the presser foot pressure or use a walking foot.
How do you stop viscose from stretching out of shape?
Staystitch necklines, armholes and curved waistlines as soon as the pieces are cut, sewing from the shoulder toward the center so the stitches do not drag the curve. Fuse lightweight interfacing to facings, and stabilize shoulder seams and the top of in-seam pockets with a narrow stay tape.
Hang bias-cut and circle garments for 24 hours before hemming. Viscose drops unevenly on the bias, and a hem leveled too early ends up wavy once the fabric settles.
Which seam finishes and hems suit viscose?
French seams are ideal on light viscose: they enclose the raw edges, which fray readily, and stay soft against the skin. An overlocker or a zigzag over the edge works well on twill.
For hems, a narrow hem of about 6 mm (1/4 in) suits flared skirts and curved hems, where a deep hem would ripple. A deeper double-fold hem, 2.5–4 cm (1–1 1/2 in), gives a straight dress or trousers more weight at the bottom and helps them hang.
How should you press viscose?
Use the two-dot setting on your iron, around 150 °C (300 °F), press from the wrong side, and use a pressing cloth on the right side to avoid shine. Lift and lower the iron instead of sliding it, which stretches the fabric. Go easy on steam on unwashed viscose, as it can leave water marks and cause extra shrinkage.
Which patterns suit viscose?
Viscose shines in garments that move: circle and gathered skirts, wrap skirts, slip dresses, fit-and-flare dresses with a gathered skirt, and blouses with puff or bell sleeves. A wrap skirt in viscose crepe is a good first project because it has few curves and no zip, and Sewly drafts it to your waist and hip so the overlap sits where it should. When you are ready for a challenge, the bias-cut slip dress uses viscose's drape to the full.