A Ron Arad sofa may fetch up to 80,000 pounds ($159,000) at a London sale this week that aims to tap demand for “design art.”

The steel work looks amazing — just don’t sit in it. “If you’re sitting on a polished metal sofa with rivets on your jeans you have to be careful,” said Ben Williams, a design specialist at Phillips de Pury .

“Sitting on these pieces tends to be reserved for special occasions. They’re usually just looked at as a sculptural element in the room.” [...]