価値を保つ切手の保管方法

Where should I keep a stamp collection?

In the main living area of your home, in a cupboard or drawer away from windows, heat sources and outside walls. Interior rooms stay closer to a steady temperature and humidity than attics, basements or garages.

Most damage to inherited collections happens in storage rather than handling. Attics overheat, basements and garages hold damp, and lofts swing between both across a year. Those swings make paper expand and contract, gum stick and mould take hold.

• Store albums upright, like books, so pages don't press unevenly. Don't stack them flat under weight.
• Keep them off the floor, in case of leaks or flooding.
• Avoid outside walls, which are colder and can attract condensation.
• Keep them away from kitchens, where grease and steam travel further than you'd think.

What temperature and humidity are right for stamps?

Around 18–22 °C and 45–55% relative humidity, kept steady. Above roughly 65% humidity, gum becomes sticky and mould and foxing can start. Very dry air makes paper brittle.

The brown spots collectors call foxing, and the general browning called toning, both come from damp storage. They can't be reversed safely, and they cut a stamp's value sharply. If you live somewhere humid, a cheap hygrometer in the cupboard tells you more than guesswork, and silica gel packs help in a sealed box.

Unused stamps suffer first, because their gum absorbs moisture. That's one reason mounts are worth using: they keep the gum off the album page. See stamp condition grades for how much condition drives price.

Which storage materials are safe for stamps?

Acid-free, lignin-free paper and card, and clear plastics made from polyester (Mylar) or polypropylene. Avoid PVC, ordinary envelopes, newsprint and anything self-adhesive.

How should I handle and check a stored collection?

Handle stamps with tongs on a clean, dry surface, and look through the collection about once a year for damp, foxing, insects or stamps starting to stick.

1. Use tongs, not fingers. Skin oils stain paper and gum over months, not days.
2. Work on a clean table with nothing to drink nearby.
3. Check album pages for a musty smell, wavy paper or brown spots, all signs of damp.
4. Watch for silverfish and other paper pests in older storage.
5. If a page feels tacky, separate it with a sheet of glassine and reduce the humidity.

What if stamps are already stuck down or damaged?

Don't force anything. Stamps stuck to album pages, to each other or to clear sleeves can sometimes be released by a specialist, but home attempts usually cause thins and tears.

For common stamps, the loss is small and not worth the risk. For anything that might be valuable, take the whole page or block to a dealer or expertizing service instead of pulling it apart. Never try to clean, bleach or iron a stamp: experts spot the treatment, and the value goes with it.

Do I need records or insurance for a stamp collection?

If the collection is worth more than a few hundred dollars, keep a photographic record and a written inventory, and check whether your home policy covers collectables, which often have a low default limit.

Photograph album pages and any valuable single stamps, keep expert certificates with the inventory rather than loose in the album, and store a copy of the record somewhere other than the collection. See how to organize a stamp collection and how to value a stamp collection.

How should I store covers, sheets and first day covers?

Store covers upright in cover boxes or sleeves, keep full sheets flat in acid-free folders, and never fold anything to make it fit. Folding is permanent damage, and a crease through a stamp destroys most of its value.

• Covers and first day covers: upright in a cover box, or in PVC-free sleeves in a binder, so the paper isn't crushed.
• Full sheets and panes: flat, in acid-free folders large enough to hold them without bending the selvage.
• Blocks and multiples: flat in mounts or stockpages, never stacked loose where perforations can catch.
• Certificates and paperwork: with the inventory, not tucked inside the album where they crease.

Large items are the ones most often ruined in storage, because they don't fit the album and get folded once “just to put them away”. If something is too big for your system, change the storage rather than the item. See first day cover value.