Repair and restoration: what is acceptable

Guides · 8 September 2026

Three different things get called repair. Conservation stops an object getting worse and changes nothing about how it reads. Restoration changes appearance to compensate for loss, and is legitimate only when it is declared. Concealment hides damage so a buyer will not see it, and that is a defect regardless of how skilfully it is done. The whole ethic of the hobby sits on keeping those three apart.

What an amateur may safely do

• Improve the environment. Dry, dark, stable, inert materials, no pressure. This is the highest-value intervention available and it carries no risk – the rules in the guides to storing paper and storing metal.
• Remove loose surface dust from paper with a soft brush, always working outward from the centre and never over a tear.
• Separate items that are touching before they stick or scratch each other.
• Photograph the current state before anything else, so the condition is documented – the method in the guide to photographing a collection.
• Stop and ask. If an intervention cannot be undone, it is not an amateur job.

What always makes things worse

1. Adhesive tape. The single most destructive material in the hobby. It yellows, stains through the paper and its adhesive migrates. A taped tear is worse than an open one.
2. Glue and paste of any household kind, on paper or metal.
3. Ironing and pressing. Flattens the visible crease and leaves broken fibre – the reasoning in the guide to banknote condition.
4. Washing, bleaching and solvents on anything printed. Ink and paper react unpredictably and irreversibly.
5. Abrasives, polishes and lacquer on metal, as set out in the guide to cleaning old coins.
6. Trimming edges to tidy them. Perforation and margins are evidence, as in the guide to perforation.

What belongs to a specialist

Tear repair with correct tissue and reversible adhesive, deacidification, mould treatment, filling losses, flattening rolled posters, stabilising active corrosion on metal. Every one of these is doable and every one requires materials and reversibility judgements that home methods do not offer. The test is simple: a professional intervention can be undone by another professional, and a household one usually cannot.

Why disclosure decides value

Restoration is not fraud; undeclared restoration is. A repaired item described as repaired keeps a place in a collection, while the same item sold as untouched destroys trust the moment the repair is spotted – and it will be spotted, because repairs show under raking light and transmitted light exactly like the checks in the guide to telling an original from a copy. Record every intervention in your catalogue, per the guide to cataloguing a collection: what was done, when and by whom.

When leaving it alone is right

• Old folds and creases on paper that has stabilised.
• Patina on metal, which protects the surface beneath.
• Postal markings, pencil notes and inscriptions – part of the object's history, not dirt.
• Anything whose damage is minor relative to the risk of the fix.

Large-format material makes the point clearly: the open archive holds 417 Soviet posters and 216 postcards, and the posters are the group where rolling, tearing and taping have done the most damage over time – as well as the group where good storage helps most.

Open the sections: posters, postcards, stamps.