Should you buy single yarn or two-fold? “Folding” two singles together changes a yarn’s strength, smoothness and cost — and the right choice depends on your fabric.
Single vs double, defined
Single yarn is one strand as spun. Double (two-fold / TFO) yarn twists two singles together on a two-for-one twister, giving a stronger, smoother, more balanced yarn. A two-fold of two 40s singles is written 40s/2.
How folding changes the yarn
- Strength & evenness: higher — folding averages out weak spots.
- Smoothness: better, with less hairiness.
- Cost: higher, due to the extra twisting step.
When to use each
Use single yarn for most knits and everyday weaving where cost matters. Use two-fold for high-strength warps, fine high-quality shirting, sewing threads and fabric where smoothness and durability justify the cost.
Specifying it
Quote the count and fold together (e.g. 30s single or 60s/2). If you are unsure, share the fabric and end use and we will recommend. Convert counts across systems with our Yarn Count Converter.
We supply single and two-fold (TFO) yarn in cotton and blends.
More in our yarn guides.