Louis Collins has been selling used books out of a storefront on Capitol Hill since 1984. It’s easy to miss — Louis Collins Books is a squat building at the corner of 12th and Denny, with nothing but a small white sign to identify it. Though Collins comes in to the store nearly every afternoon, the store is only open by appointment, so you can’t just wander in and check out the shelves of books visible from the street. If you’ve shopped for antiquarian books online, though, chances are good that you’ve encountered one of Collins’s titles. He lists some 23,000 titles on a number of online sites and his own site.

Collins co-founded the Seattle Antiquarian Book Fair almost four decades ago, and he works on the show year-round. This year’s edition happens this weekend at Seattle Center, but as soon as this year’s show is through, Collins says he’ll start work on the next one. The Antiquarian Book Fair is an extension of Louis Collins Books, and it’s a real point of pride for him.

Collins says this year’s Book Fair will have “kind of an ephemera focus,” with a special appearance from the Ephemera Society of America. He says they’ll exhibit different library collections including Civil War letters, obscure Pacific Northwest baseball ephemera, and other paper goods from times long past.

For first-time visitors to the Seattle Antiquarian Book Fair, Collins recommends that you “just look and see what strikes your fancy. Look at the program and follow your interest.” Collins says you’ll find plenty of specialty dealers at the fair, for those with particular interests like arctic travel or railroads, but many of the almost 100 dealers are general-interest, so “it’s best to just look around. You’ll see things that you will not see again.” And if you see something that’s in a glass case, don’t be shy, Collins says. “If you see something that piques your interest,” Collins says, “just ask the dealer about it. They’ll show it to you and tell you about it. They’re pretty good at that.”

Collins is proud of his collection at Louis Collins Books, but you can tell that he believes the Antiquarian Book Fair is really something special. For the weekend that it’s around, he says, when all the dealers combine their stock under one roof, “it’s the best bookstore in America.” And then, “when everybody packs up and goes home, it’s gone.”