Stuffed in a desk in North Germany is a small box with one of the world's most unique and perplexing collections. Charlotte Ruchhöft has collected more than 500 balls from fountain pens.

It was the TWSBI Diamond 580ALR, a sleek but hefty fountain pen with an aluminum grip and a ... the reminder to “Scoop the cat’s litter box” shimmers with golden flecks, making the ...