Red Powdery Leather on an Old Bag: Red Rot?

Red rot is a condition in which some vegetable-tanned leather degrades and produces a red, powdery surface. The Canadian Conservation Institute says that, depending on the tannin used, vegetable-tanned leather may be prone to it, and that such leather should be brushed very gently to prevent extensive loss of fibres.

What the CCI says

• Vegetable-tanned leather is made by soaking prepared skins in tannin-rich liquids made from bark, leaves or twigs.
• Depending on the type of tannin, the leather may be prone to red rot, a degradation that eventually produces a red, powdery surface.
• Leather with red rot should be brushed very gently to prevent extensive loss of leather fibres.
• Current museum practice is to minimise dressings and cleaners because of their long-term effects.
• More drastic treatments, including repairs, should not be undertaken without consulting a conservator.

What to do

1. Handle the bag as little as possible.
2. Support it fully, since weak leather can tear under its own weight.
3. Use only a soft brush and very gentle strokes to remove dust.
4. Do not apply dressings, oils or soaps.
5. Ask a conservator or a specialist repairer about the bag.

What to avoid

Do not wear or carry a bag with red rot under load, since the leather may tear without warning.

Sellers of vintage bags may not mention red rot, so ask about it before you buy and look at the underside of straps and the inside of flaps, where the leather is often least protected. If the bag is a gift or an investment, have it checked by a specialist before you commit.

Where this answer stops

The CCI gives a general description. We cannot tell you whether your bag has red rot from a description, and modern leather is often tanned in other ways. A specialist can examine it.