Sewing with Tencel (lyocell): drape without the tears

Tencel is the brand name of lyocell, a cellulose fiber spun from wood pulp, and it gives you the cool, fluid drape of viscose with far fewer of viscose's problems: it shrinks less, holds its grain better, creases less and is stronger when wet. Sew it with a fine sharp needle, a microtex 70/10 or 80/12, polyester thread and a 2.5 mm stitch, cut it in a single layer because it still slides, and press it on a medium setting through a cloth. French seams and narrow hems suit the light weaves; the popular twill takes an overlocked seam and an ordinary double-fold hem.

Quick reference: how to sew Tencel lyocell

What is Tencel, and how is it different from viscose?

Lyocell is a regenerated cellulose fiber, like viscose and modal: wood pulp, usually eucalyptus or beech, is dissolved and spun into a filament. The difference is the process. Lyocell uses an organic solvent in a closed loop that recovers almost all of it, instead of the carbon disulfide process of viscose, and the resulting fiber is more uniform and stronger. Tencel is the trade name of the lyocell made by Lenzing; "lyocell" on a label is the generic fiber, often the same thing.

For the sewing table, three differences matter. Lyocell is strong when wet, so it survives washing without the stretching and shrinking that make viscose such a gamble; expect 2 to 4 % shrinkage rather than 5 to 10. It is more stable on the cutting table, keeping its grain instead of skewing. And it is smoother, so it drapes even more fluidly and shows every pin hole and iron mark on the shiny weaves.

You will meet it in a few weaves. Tencel twill, 160 to 220 g/m² (4.7 to 6.5 oz/yd²), is the most common, with a soft diagonal rib and a heavy, swinging drape that has made it the default fabric for wide-leg trousers. Tencel sateen is lighter and lustrous, close to a washable silk. Plain-weave Tencel and linen-Tencel blends are crisp and cool for shirts; Tencel jersey behaves like a slinky viscose knit.

Should you pre-wash Tencel?

Yes, in the way you will wash the finished garment: a gentle cycle at 30 to 40 °C (85 to 105 °F), the fabric folded inside out if it has a right side, a mild detergent and a low spin. Hang it or tumble on low, and press it while it is still slightly damp, which takes out creases far more easily than steaming the dry fabric later.

One lyocell habit to know about: the fiber can show pale, chafed-looking marks where wet fabric rubs hard against itself, a surface effect called fibrillation. A gentle cycle, a machine that is not overloaded and no hot tumble prevent it. The pre-washing guide covers washing lengths of fabric without tangling.

How do you cut Tencel without it shifting?

Tencel is better behaved than viscose but it still slides, and the heavy twill drags under its own weight. Cut on a large flat surface with nothing hanging over the edge, in a single layer for anything bigger than a pocket, with pattern weights and a rotary cutter if you have them. A layer of tissue paper or a cotton sheet under the fabric stops it skating on a smooth table. The slippery fabric tutorial has the full routine, and the twill needs only the first half of it.

Find the grain from the selvage, not by eye: the diagonal rib of a twill leads the eye off grain. Mark with chalk or a washable pen, tested on a scrap, and use fine glass-head pins placed inside the seam allowance, because the sateen in particular keeps the holes. Staystitch necklines and the top of skirts straight away; both stretch while you work.

Which needle, thread and stitch length work for Tencel?

A microtex (sharp) needle makes the cleanest holes in a smooth, dense weave; a 70/10 suits sateen and plain weaves, an 80/12 the twill. A universal needle in the same sizes also works, but a blunted needle shows at once as pulled threads along the seam. Polyester all-purpose thread has the right strength and a little give; use it at 2.5 mm, with the tension slightly reduced if the seam puckers on a light sateen. For topstitching on twill, which looks excellent, lengthen to 3 mm and use the same thread, or a topstitching thread with a 90/14 topstitch needle.

If the top layer creeps ahead of the bottom one on long seams, lower the presser foot pressure if your machine allows it, or use a walking foot. The needle and thread guide has the full table if you are matching a blend.

How do you finish seams in Tencel?

Lyocell weaves fray moderately. For twill, the simplest finish is an overlocked or zigzagged edge, pressed open or to one side; it washes well, and the twill is too heavy for a French seam. For sateen and the light plain weaves, a French seam is the right finish: enclosed, soft against the skin and invisible through a thin fabric. A flat-felled seam suits Tencel shirts and the outside leg of trousers, and takes topstitching beautifully. Trim and grade the allowances in waistbands and facings, since the twill builds bulk across several layers.

How do you press Tencel?

Use a medium setting, between the silk and cotton marks on most irons, around 150 °C (300 °F), with steam. Press from the wrong side, and through a pressing cloth whenever the iron meets the right side, because the sateen and even the twill take on shine and show the imprint of seam allowances. Press, lift and move; do not slide the iron along a bias seam. Fusible interfacing bonds well at this temperature with enough pressure and time; choose a light, soft weft interfacing so that collars and facings keep the fabric's drape.

How do you hem Tencel?

The twill takes a plain double-fold hem, 1 cm (3/8 in) then 2.5 cm (1 in), topstitched at 3 mm, and the weight of the fabric makes it hang straight. Sateen and plain weaves want a narrow hem: stitch 6 mm (1/4 in) from the edge, fold on the stitching, fold again and edgestitch, or use a rolled-hem foot. Anything cut on the bias, such as a slip dress, should hang for 24 hours before you level and hem it, because the drape that makes Tencel attractive also makes the bias sections drop. The hemming guide covers all three.

What should you sew with Tencel?

• Wide-leg or straight trousers in Tencel twill: the fabric that made the garment. Pull-on trousers in the wide or straight leg use the drape fully, and an elastic waist disappears under the soft folds. Sewly drafts the pattern with 1.5 cm (5/8 in) seam allowances, which leaves room for a flat-felled outseam if you want the topstitched look.
• A slip dress in Tencel sateen: a bias-cut slip dress in washable sateen gives the look of silk and goes in the washing machine.
• A shirt, blouse or wrap skirt: a button-front woven top in a plain-weave Tencel or a linen blend, or a wrap skirt in twill that swings as you walk.