In the world of book collecting, one trend seems to recur: our literary favorites are one day likely to become the collectibles adorning our bookshelves.

The year 2016 marked the anniversary of the births of two of the most beloved children’s authors of all time: Roald Dahl, author of classics like Charlie and the Chocolate Factory and Matilda, who would have turned 100 years old on September 13, 2016; and Beatrix Potter, renowned writer and illustrator of The Tale of Peter Rabbit, who would have turned 150 in July 2016.

Stemming from the fanfare around these milestones, as well as a renewed, nostalgic interest in these authors, recent book auctions have focused on children’s, illustrated, and picture books. Top sales have featured editions by the beloved Dahl and Potter, among other reputed authors and illustrators of the 19th and 20th centuries.

Seasoned bibliophiles around the world have flocked to win these rare editions of children’s and modern adult classics, but those who are new to collecting 19th- and 20th-century rare books may question where exactly to start. To help provide some guidance, we turned to Deborah Macke, manager of the London branch of Potterton Books, a bookseller of over 30 years which specializes in “books for inspiration”; Max Hasler, specialist in modern first editions at the recently established London-based Forum Auctions; and Cathy Marsden, specialist in Rare Books and Works on Paper at Lyon & Turnbull.

Tips for New Collectors

Buy what you love.

It may seem obvious, but the first piece of advice from each of our specialists was to make sure everything you buy speaks to you. Popular purchases that you think might make you a quick buck have their own karma and, as Hasler says, “They may stay on your bookshelf a lot longer than you expect!” If you purchase something you enjoy, you’ll offset any pressure sell right away.

Ask questions.

According to Hasler, there are some basic questions you should ask yourself when considering a new edition to your collection, especially if your goal is ultimately to offer it for resale:

Why would another person want to buy it?

Is it beautiful?

Is it unique?

Was it illustrated by an artist/illustrator of note?

Is it informative, or would it appeal to a niche area of interest?

How old is it?

Of what quality is the printing?

Go niche, and do your research.

Once you’ve found a field you love, get to know it intimately. The best way to research your niche, says Marsden, is to find a bibliography you can trust and use that as a guide. You can normally find reference to one of these in an auction catalog.

Condition is paramount.

If you’re looking to re-sell, the importance of condition cannot be overstated. Up to 80 percent of the sale value of a book can depend upon the presence and condition of a dust jacket. So if you’re starting to collect, look for books with their original dust jackets, and try to find them in the best condition possible.

Keep an eye out for the unique.

Rarity is crucial to increasing value. Start by learning the basics behind identifying first editions, number lines, original dust jackets, advanced review copies, and more. A good place to begin learning is by exploring auction house sales results. You can also check out the latest edition of “Collected Books: The Guide to Identification and Values” by Allen and Patricia Ahearn.

While fully understanding what makes a particular 19th- or 20th-century book rare, however, will come with years of experience as a book collector, it’s never too early to start learning the ropes.

Traps for New Collectors

An age old question.

One of the fallacies that often stumps new collectors is the “age = value” assumption. Hasler points out that since the advent of the Gutenberg Press, books have been printed in relative abundance. This means that a book up to 500 years old book may not be as scarce, or as valuable, as you might hope. That being said, books dating back to 1450-1500 often prove to be of surprisingly great value.

Limit your limited editions.

As with old books, 20th-century limited editions may not prove as rare or sought after as one might assume. For example, notes Marsden, Harry Potter‘s first print run consisted of 500 hardback books. Although these were not officially marked or considered limited editions, Harry Potter aficionados are all too aware of their existence and rarity. Subsequent print runs of Harry Potter, marked “limited edition,” are still of lower value than the unmarked first editions.

Don’t spend it all at once.

While buying the best quality you can afford is a sage advice for the new collector, so is the slightly contradictory warning: “Don’t spend it all at once.” Buying too ambitiously can stilt your progress if you’re looking to build out a collection. Besides, it’s not exclusively about the biggest and best, as “there’s also something in the thrill of the chase,” suggests Hasler. In other words, you can also find joy in a niche discovery, regardless of its resale value, if it adds a depth to your collection.

See, and Be Seen

In the past, people often came to Potterton Books with questions, ready to take advice. But according to Macke, today’s customers come with fewer queries, perhaps because they believe they have discovered all they need to know online or are distrustful of advice in an era of free information. But, she adds, many specialists still come to Claire Jameson (the founder of Potterton Books) for help with rare and unusual finds.

Online platforms such as Invaluable offer advanced search functions that enable people to find exactly what it is they want. But, advises Hasler, if you don’t yet quite know what it is you’re looking for, then talking to the specialists at auction houses or bookstores directly can still inform and guide you toward unexpected gems.

Attending book fairs is also great way to familiarize yourself with the industry and help you to learn who operates in your niche. “Don’t be afraid to say hi! Everybody’s very friendly. They just want to talk about books!” says Marsden. “You don’t have to go to buy, but it’s good to get a feel for a range of books and a range of dealers from across the world,” says Hasler.

Making Predictions

With the newly sparked interest in Roald Dahl, Hasler predicts collector interest will surge for Harry Potter editions in 30-40 years (keep hold of your books, Potterheads!).

For the nostalgic folk looking to build out a collection of children’s books beyond Roald Dahl or Beatrix Potter, our specialists suggest tracking down the following authors and books:

Edmund Dulac

Arthur Rackham

Ronald Searle’s Molesworth and St. Trinians

A.A. Milne’s Winnie the Pooh (Pro Tip: Keep an eye out for a full set of first editions with dust jackets)