Q: About 25 years ago, I bought a modern-looking side table just because I liked it. The other day I noticed that it’s signed “Johan Tapp.” What do you know about him?

A: Johan Tapp (1888-1939) was a Dutch designer. His furniture designs, many with a midcentury modern look, were apparently manufactured and sold by various companies. Today his pieces can sell for $200 to $2,000 or more.