Of the hundreds of unique “impossible bottles” her husband assembled over the years, Kathy Brown loves the one he gave her the best.

It’s not only because she can still remember the day he surprised her with it — filled with items representing her Chinese heritage and their life together — or because after his death, she placed their wedding rings inside. And it’s not just because the bottle’s delicate, curved neck and shape show Chris Brown’s high skill level at an extremely difficult hobby.

It was the personal touch that Chris put in the bottles that made them so special, said Brown, who wrote “A Love Story of Impossible Bottles.” The book is dedicated to and inspired by her husband, who died in a parachuting accident in July 2012 at age 52.

“I really feel like these bottles symbolize the heart,” Brown said. “Usually we don’t let everything in, so when something is special, you want to capture it, and I think that is the whole idea.”

Impossible bottles, which get their name by appearing to defy logic by having objects inside that are too large to fit through the bottleneck, take patience — and lots of it. The best-known impossible bottles are those with ships inside, but many other objects will work. It’s a matter of deconstructing an item and then working painstakingly inside the bottle to put it back together.

Chris started making impossible bottles in the early 2000s, and it quickly became one of his many hobbies. His son, Scott Snyder, thinks it was a stress reliever for his dad, who loved anything with a challenge.

“He would just see things and be inspired,” Snyder said. “He wasn’t into selling them and stuff and just wanted to give them to people as special gifts.”

Chris and Kathy married in 2011, but they knew each other as co-workers at Penn State University for more than a decade before that. Kathy remembers hearing that Chris made bottles, but she didn’t realize the scope of the hobby or its significance until she saw for herself.

“To put a deck of cards in, that’s really easy … but it’s the personal elements. You’re trying to get as much as possible to capture that person’s characteristics by how you design, by how you lay out,” she said. “Sometimes it takes months or years to complete.”

After her husband’s death, Brown found some of his works in progress, as well as the start of a book he’d been working on. Loose-leaf paper in a binder provided the bones for a “how-to” book, and there also were narratives that went along with bottles he had created for his grandfather and beloved dog.

“When he died, I knew I wanted to do something, and the first thing that came to mind was about his book,” Brown said.

But she wanted to take the book beyond a tutorial. She spent 10 months writing “A Love Story of Impossible Bottles,” which includes the how-to that her husband had started, paired with stories of favorite, special bottles.

“We all tried to figure out ways to handle the grief, and I think [the book] was a pretty awesome way to carry on his legacy and fulfill his dreams,” Snyder said.

Brown said she experienced a type of catharsis while writing the book and using the techniques Chris had taught her.

“I remember he said if you get frustrated, put it away, don’t do anything or you’ll regret it. I just felt the little jolt and then I put it away,” she said. “The next day I woke up with different ideas to continue the work and try different methods.”

She published the book in 2013, hitting her self-imposed deadline of releasing it a year after Chris’ death. She released the second edition in November. The book is available through Amazon, Barnes & Noble and other major distributors.

She continues to make impossible bottles, including completing some of those Chris never had the chance to.

“When I retired from the Air Force, Kathy finished a bottle that was one my dad had started for me,” Snyder said. “That is one of my prized possessions.”