Why Does Leather Crack at the Folds of a Bag?

Dry air and sharp, unpadded folds make leather crack. Pad the folds, keep humidity steady and avoid creasing a bag in storage.

Published November 3, 2026 · 3 min read · Topic: Repairs, Zippers & Hardware · Repairs & hardware

Typical situation

The leather on the side gusset of your bag has started to show fine cracks along the lines where it folds every time you open the bag.

Main answer · berabags Editorial Team · Repair view

Sharp folds, dry air and swings in humidity all stress leather. The Canadian Conservation Institute says that sharp folds or creases should be padded to avoid cracking and eventual splitting, and that very dry conditions below 30 per cent relative humidity cause embrittlement. Prevention matters more than repair.

What the CCI says

Very dry conditions of less than 30 per cent relative humidity cause loss of moisture and embrittlement.
Fluctuations in humidity may lead to buckling or splitting where leather is stitched to another material.
Sharp folds or creases should be padded to avoid cracking and eventual splitting.
Folds and rounded objects should be padded with unbuffered, acid-free tissue, and pouches filled with polyester batting or rolls of acid-free paper.
Research has shown that dressings are generally not effective in preserving leather.

How to reduce the risk

Store the bag stuffed, with its folds open and padded.
Keep it away from radiators, heaters and strong sun.
Avoid sudden changes between damp and very dry conditions.
Do not fold or crush the bag in a drawer.
Check the folds when you take the bag out.

If cracks have already formed

A crack cannot be reversed by cleaning or by oil. A repairer can sometimes reinforce a weak area from the inside, so ask about this before it opens up.

If your climate is very dry, or you live with heating on for much of the year, check your bags more often. Leather that is stored in a dry room can lose moisture and stiffen, and the folds are where the first cracks will show up.

Where this answer stops

The CCI note describes museum leather. A bag that is used daily will bend and crease, and some wear is normal. Your climate also affects how dry the air is.

Sources and further reading

Canadian Conservation Institute: Care of alum, vegetable and mineral-tanned leather (CCI Note 8/2)

Three more perspectives

berabags Editorial Team · Maintenance view

Stuff the bag lightly when you store it so the folds are open and padded. A bag that is stored flat and creased puts the same line under stress for months.

berabags Editorial Team · Selection view

Look at where the cracks are. Fine cracks along a fold on an old bag are a sign of age and dryness, while deep splits point to damage that needs repair.

berabags Editorial Team · Risk view

A dressing is not the cure. The note says that dressings are generally not effective in preserving leather, so do not expect oil to repair a crack once it has formed.

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