Silk Yarn

How silk behaves on the needles

Silk is a long, smooth, strong filament with almost no crimp, and every quality it has follows from that. It reflects light, so colours read deeper and more luminous than the same dye on wool. It has enormous tensile strength, so a fine silk shawl outlasts its owner. And it has no elasticity whatsoever, which is the thing most knitters discover the hard way: pure silk does not spring back, so ribbing goes slack, a fitted waist drops, and a heavy garment lengthens on the hanger. Once you plan around that, silk is a joy.

Pure silk or a blend

• Pure mulberry silk: the highest sheen and the smoothest surface. Best in shawls, lace and drapey tops where weight is an advantage.
• Silk with merino: the blend adds bounce and memory, making it viable for jumpers, cardigans and anything with ribbing.
• Silk with alpaca: maximum drape and warmth, wonderful in a loose shape, unforgiving in a fitted one.
• Silk with mohair or cashmere: a halo or extra softness over the silk core; the classic lace-weight combination for airy wraps.
• Tussah and wild silks: more texture and a warmer, honeyed tone, with a slightly rustic handle.

Projects that suit it

Silk earns its price in shawls, stoles, lace scarves, summer tees, camisoles and evening tops. It is cool against the skin in heat because it moves moisture away, and it insulates in cold because of the same fibre structure, which is why it turns up in both summer and winter knitting. It is a poor choice for socks worn alone, for cuffs that must grip, and for a heavy oversized coat that will stretch downwards under its own weight.

Tension and needles

Swatch, and then hang the swatch. Wash it, dry it flat, then peg it up with a small weight for a day and measure again; that second measurement is what your finished garment will do. Slippery metal needles can make silk feel uncontrollable, so many knitters prefer wood or bamboo for grip. Work at a slightly firmer tension than you would in wool, since loose silk fabric grows further. For lace, silk is superb: it blocks hard and holds every point.

Substituting silk into a wool pattern

Match the tension rather than the stated weight, and then read the pattern for anything that relies on elasticity: deep ribbing, a gathered sleeve head, a fitted waist or a snug neckline. Those are the details that go soft in silk. Where a pattern is written in stocking stitch with a straight body and a wide neck, a silk or silk blend substitution usually flatters it. Buy to the metres listed, not the ball count, because silk is dense and a 50g ball can carry very different yardage from the wool it is replacing.

Blocking and care

Silk blocks dramatically. A crumpled lace shawl opens up into something twice the size, and the sheen improves after a wash. Soak in lukewarm water with a wool wash or a very mild shampoo for ten minutes, press the water out between towels without wringing, and pin out to the schematic. Never wring silk and never hang it wet. Dry away from direct sunlight, which weakens the fibre and fades dyes faster than it does with wool. Store folded, flat, and away from anything that will snag the surface.

Silk yarn questions

Is silk yarn warm or cool? Both. It moves moisture away in heat and traps air in cold, which is why it is used year round.

Why does my silk garment stretch? Silk has no elastic memory. Choose blends with wool for structured pieces, and swatch under weight before committing.

Can I machine wash it? No. Hand wash gently in lukewarm water and dry flat unless the ball band explicitly says otherwise.

What is the difference between mulberry and tussah silk? Mulberry is cultivated, paler and glossier; tussah is wild, warmer in tone and slightly more textured.

Which needles work best? Wood or bamboo, for grip on a very smooth yarn, especially in lace weight.

Where to go next

Silk is nearly always a blend here — with merino, cashmere or alpaca. For the same drape without silk, try bamboo and linen. By weight, silk blends are concentrated in lace weight, 4 ply and DK.