For Bob Grove, it all started on a trip to Europe when he graduated from college in 1967.

He picked up maps at train stations, and found that the airsickness bags from airline seat-back pockets were perfect for corralling the maps.

“When I got home, I had this little collection of barf bags,” said Grove, a 69-year-old retired attorney also known as Barf Bag Bob. “I put them on my bathroom wall, sort of satirizing collecting.”

Eventually he picked up more, and soon enough, 48 years later he had more than 2,000 barf bags from airlines around the world. About 700 of them cover the walls of his bathrooms.

“There’s a thin line between collecting and dysfunctional hoarding,” acknowledged Grove, who figures he has the largest collection of barf bags in the lower 48 states and pays anywhere from $2 to $30 per bag. “It’s a hobby, not an obsession. Not yet.”

Grove is one of the many avid airline memorabilia collectors gathered at the Delta Flight Museum near Hartsfield-Jackson International Airport at the Airliners International show.

Collectors at the Airliners International show sold everything from airplane models to T-shirts, in-flight china, posters, barf bags, postcards, model kits, pins and playing cards at the show June 18-20.

The international show visits a different city each year, and organizer Chris Slimmer said the event features dealers from more than 20 countries. It’s about four times the size of the annual local airline collectibles show at the Delta museum each fall, Slimmer said.

For the Delta Flight Museum, which reopened after major renovations one year ago, the show attracts people from all over the world to visit, said museum president John Boatright.

“As the Delta Flight Museum, we’re out here looking at things for our archival collection, to fill in things we don’t have,” Boatright said.

Grove traveled from San Diego to the show to acquire even more barf bags. He thinks the best type of collectibles are items that when manufactured, were never meant to be collected — as barf bags surely weren’t.

Grove finds aesthetic benefits in his barf bag collecting hobby. “It’s really a study in graphic design,” he said, describing the intricacies of the dots in an airline logo on one barf bag. And, “When you collect, you sort of learn the history of airlines.” For example, defunct airlines’ barf bags are often more expensive.

“There are some people that find it a little disturbing,” Grove said. “That tends to be their problem, not my problem.”