Leathercraft and Construction
Stitches Per Inch on a Leather Jacket: What SPI Tells You About Quality
How to count stitches per inch on a leather jacket, convert stitch length to SPI, and what the number does and does not say about seam quality.
Fig. 01 — Craftsmanship
Know good leather when you see it.
How leather is graded, tanned and stitched, and how to recognise craftsmanship that lasts.
What you’ll find here
How leather is graded, tanned and stitched, and how to recognise craftsmanship that lasts.
Latest articles
Tanning and Production
Why Tanners Once Used Urine and Dung: Tanning Before Chemistry
Tanners used urine to loosen hair and dung to soften hides. See what each step did, why it worked, and what modern enzymes replaced it.
Tanning and Production
Metal-Free and Chrome-Free Leather: Wet-White Tanning and What the Label Means
Chrome-free leather skips chromium salts. Learn what wet white is, why 'metal-free' has no agreed definition, and how these leathers perform.
Tanning and Production
Oil-Tanned Leather: What Oil Tannage Is, Why It Pulls Up and How It Differs From Pull-Up Finishes
Oil-tanned leather means two things: true oil tannage as in chamois, or oil-and-wax packed leather. See how they differ and why sources disagree.