A fabric spec sheet packs a lot into a few lines. Reading it confidently helps you order the right yarn and avoid costly mismatches. Here is what each term means.
The key terms
- Count: yarn fineness (e.g. 30s Ne). See our count converter.
- GSM: fabric weight per square metre. See GSM converter.
- EPI / PPI: ends per inch (warp) and picks per inch (weft) — the weave density.
- Width: finished or greige width, in inches or cm (convert here).
- Construction: often written as warp count × weft count / EPI × PPI.
Reading a woven construction
A line like 40 × 40 / 132 × 72 means 40s warp and weft, 132 EPI and 72 PPI — a fine, dense poplin. Higher EPI/PPI and finer counts mean lighter, finer fabric. Use the Reed Count Calculator to plan the reed from EPI.
Knits are different
Knit specs lead with GSM, gauge and yarn count rather than EPI/PPI. In both cases, count and GSM together tell you most of what you need.
From spec to order
Once you understand the spec, size the yarn order with the Yarn Requirement Calculator and cost it with the Cost Estimator.
Send us your fabric spec and we will recommend and quote the yarn.
All calculators are on our buyer tools page.