"I use quick-drying glue so that they stick immediately," Hoel told Norway's TV 2 channel, while gluing pen number 25,000 to the wall of his cellar.
Svein Hoel from Fauske outside Bodø has been an avid collector since he was a boy, but only moved from stamps to pens in 2000 when his wife asked him to find a new hobby.
Each pen is recorded in a handwritten system with its own number and space. ￼
"There are many people who wonder if I have a screw loose and maybe I do," he chuckled during the interview.