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Footwear defects: a guide by area and cause

A defect caught at the stage where it starts costs far less than one found at dispatch or in a return. This guide brings together the most common footwear defects, organised by the part of the shoe where they appear: what they are, where they come from and how to prevent them.

Every factory sets its own acceptance criteria: treat this guide as a starting point, not a standard.

Scratches, stains, creases and holes in the leather or upper material. Many come from the raw material or from handling between operations.

See upper defects →

Loose or skipped stitches, thread ends on show and uneven seams. Cosmetic defects that can open up with wear.

See stitching defects →

Glue past the bonding line and soles that come apart. A multi-step process where every step counts.

See bonding defects →

Cracks, scratches and warped soles. Defects that come from the material, from storage or from assembly.

See sole defects →

Mould marks, uneven paint and dirt. The last chance to catch a defect before the box.

See finishing defects →

  • Shoe deformation. Heel counters or toe caps that have lost their shape, or a shoe that doesn't hold the line of the design. Often caused by taking the shoe off the last too early or by insufficient heat setting.
  • Pair asymmetry. Differences between the left and right shoe in height, component placement or shade. It only shows when the pair is compared side by side.
  • Eyelets and components. Eyelets that are loose, crooked, cracked or missing, and other badly applied components. They come from setting and machine adjustment.
  • Colour and shade. Shade differences between parts of the same shoe or between the two shoes of a pair, often from using hides or dyes from different batches.

The best time to catch a defect is straight after the stage that creates it (after cutting, closing, lasting and finishing), not only at final inspection. AI visual inspection helps you do that to the same standard on every shift, and keeps a record of where and when each defect appeared.

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TreadlyAI is in early access. Tell us how you inspect today and we'll show you how it could work in your factory.

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