📖 Craft & Story · 🕐 Reading time: 4 min. · 🏷 Technology & Craft
Not all seams are created equal. When you buy a leather wallet, you usually buy a seam too—and only notice it when it breaks. This article explains the difference.
Machine vs. Hand
Most leather goods are machine-stitched. This is fast, inexpensive, and results in visually uniform seams. But there's a structural disadvantage.
Machine Stitch
The Lockstitch Principle
Industrial sewing machines use an upper thread and a lower thread that interlock within the material. If a single stitch breaks, the material gives way, the thread unravels, and the seam opens stitch by stitch. With leather, which is bent daily, this happens sooner than with other materials.
Saddle Stitch
Two Needles, One Thread
The saddle stitch works differently: one needle from the front, one from the back, the thread crosses in each opening. If one stitch breaks, the adjacent stitch secures the seam. It doesn't unravel backward—it holds, even if individual points are damaged.
The Preparation
The bulk of the work happens before the first stitch.
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Creaser
A narrow groove is drawn into the leather along the seam edge with a creaser. The seam sinks into it—sits deeper, is better protected, and wears less.
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Pre-punching
The holes are pre-punched with a punching tool. The spacing determines the seam appearance: closer looks finer, wider provides more hold in the material. KATAAB uses a fixed standard for each product type.
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Thread Selection and Preparation
Waxed linen thread for most pieces—resistant to moisture, friction, and UV light. The thread is drawn over beeswax before sewing so that it glides smoothly when pulled through and sits compactly after setting.
What Hands Feel
A machine seam cannot sense if the leather is thicker in one spot, if there's a flaw in the material, or if the thread is too tight. Hand-sewing can. The tension is regulated individually with each stitch—tighter for thick layers, even for thin ones. This sounds like a detail. It's why hand-sewn leather goods age differently.
The Material of the Seam
Linen Thread
For Wallets and Small Accessories
Linen is durable, non-stretch, and weathers slower than synthetic threads. With good care, a linen seam on vegetable-tanned leather lasts longer than the leather itself.
Waxed Polyester Thread
For More Heavily Used Items
More tensile strength for the same cross-section. Used at KATAAB for pieces with particularly high stress on edges and carrier seams.
Sustainability Through Slowness
“The seam was still intact after four years—I brought the wallet to Seiha and he explained how I could care for it myself.” — Customer, Munich
A piece that lasts 15 years means one less piece that needs to be produced. This is the most sustainable aspect of artisanal quality: not the origin of the material, but its lifespan.
Discover All Pieces
Every KATAAB piece is sewn with a saddle stitch. To the collection → · Materials & Care →
KATAAB · Berlin