Everything you need to know about old postcards

These guides answer the questions people ask most when they find a box of old postcards, inherit an album, or start wondering whether a collection is worth anything. Each one starts with a short, direct answer and then goes into the detail for anyone who wants it.

They are written from the point of view of a collector. I buy complete postcard collections by mail from anywhere in the United States, and as a collector I know which cards collectors chase and which ones nobody wants. Where I have a stake in the answer, for example when comparing ways to sell, I say so plainly and give you the other options fairly.

A few principles run through all of them:

• Most old postcards are common. The value in a collection usually sits in a minority of its cards, often the plainest-looking ones.
• Real photographs matter most. Real photo postcards of identifiable small towns, businesses, people at work and events are the most sought-after American cards.
• Condition matters, writing does not. A message and a postmark on the back are normal and often welcome. Creases, tears and stains on the front are what lower value.
• Keep collections together. Pulling out the best-looking cards almost always removes the wrong ones and lowers what's left.
• Never clean, trim or repair old cards. Leave them exactly as found.

If you're short on time, read the five guides listed under Start here. If you have a specific question, such as whether a linen card is valuable or how to date a real photo by its stamp box, the guides below are grouped by topic.

And if you'd rather skip the reading and simply find out what your collection is worth, the quote form takes about ten minutes. It's free, and nothing is owed unless you decide to sell.

How these guides are organized

Selling covers the practical side: where to sell old postcards, who buys them, how to do it step by step, selling on eBay, what an appraisal is and when you need one, and what to do with a box of cards you have just found.

Value is about money: whether old postcards are worth anything, which kinds are worth the most, typical price ranges, what real photo postcards bring, how messages and stamps affect value, what an album is worth, and how condition is judged.

Types goes card by card through the kinds you're most likely to find, from linens and chromes to leather and German-printed cards, holiday cards, military cards and railroad views.

Identifying and caring explains how to date a card, the history behind each era, the vocabulary collectors use, and how to store a collection so it keeps its value.

Every guide links to related ones, so you can follow a question wherever it leads.

New guides are added as questions come in. If you have a question that isn't answered here, send it through the contact page; the most common questions often become new guides.