There are ways to make a good card look even better and more appealing to bidders. In so doing an ordinary card can be elevated to super-card status and become the subject of a bidding war that turns a card that cost you a few pence into a three figure multi-bid item on eBay. But you must be very careful when cleaning these fragile items or you could eliminate all resale potential.
* Postcards often get dirty where the margins have been exposed from the sides of a pile or the album containing the cards. It’s very common to see an otherwise very clean postcard with a dirty margin, the margin being the only part of the item exposed to daily hazards like dusty, grime, water, sunlight. Most dust can be cleaned with a soft rubber or piece of dry bread.
Use a big rubber or large chunk of bread to prevent your fingers touching the card and your nails causing scratches or tears in the delicate paper. Hold the card down very carefully at both corners nearest the dusty margin and don’t rub heavily over the card or the friction will cause the paper to crumple and crease.
With eraser or bread between thumb and finger of the other hand, rub lightly in one direction across the dusty area. Do not use backward and forward stokes directly on the card, this will cause the material to tear or thin. If the dust doesn’t shift, leave it alone, too much rubbing will damage the surface and affect the picture and make it worthless.
* Real photographic postcards are often found dirty or covered in fingerprints and these are the easiest to clean. Real photographic postcards also crease quite easily, which is usually not a problem except where dirt gets trapped in creases and makes condition look worse than it really is. Again hold the card down on a hard surface, finger and thumb of one hand keeping it lightly stretched, make smooth strokes in one direction over the dirty areas using a damp kitchen towel or face tissue.
Use light strokes, do not rub or you’ll leave marks and you might even tear the card or remove part of the surface. Lanolin-based face and baby tissues are especially gentle for photographic postcards and you can apply a little extra pressure along the line of a crease with dirt engrained. Do not rub against the line of a crease or the card will disintegrate. Don’t expect to remove all the dirt, these items are very old, and fragile, too much rubbing will cause damage and deplete the value of the card.
* Most cards, with the exception of some printed and most real photographic types, were printed in layers of paper and were not really made from card at all. The top of usually three layers is the picture part, the bottom is the address part, with usually an extra layer between for support.
Layers often part company at the edges, sometimes they separate completely, usually caused by dampness. It’s difficult, almost impossible, to glue back layers that have fallen completely apart, it takes time and skill and the result is rarely worthwhile on a common card.
Most household glues are thicker than those used to create the original card and give a lumpy appearance to the finished card which also looks and feels too thick. Where layers are split at the corners and the body of the card remains intact, you can easily apply a spot of glue between each layer, smooth it out with the glue bottle nozzle, then place the card onto a flat hard surface and smooth gently over the repairs using light strokes with a clean finger. Stroke short of the margins or glue may seep out and your card become stuck to the surface and impossible to remove.