Fashion
Stitch Per Inch (SPI)
Definition
The number of stitches in one linear inch of seam. Industry standard for quality garments is 8–12 SPI. Luxury tailoring typically achieves 12–16 SPI. Higher SPI creates stronger, finer seams with less puckering.
Why it matters for dupe shopping
SPI is one of the few measurable quality metrics accessible without laboratory equipment. Count stitches on a seam with a ruler and magnifier. Budget alternatives with 10+ SPI offer comparable seam strength to luxury originals at much lower cost.