January 29, 2009: Issue 275
Use -ed in a compound adjective when you’re describing modification to an existing object:
a granite-topped buffet
The cabinets and the buffet were there before the stain was applied or the granite was placed.
When you name an integral quality, however, don’t use -ed:
a barrel-vault ceiling
There was no window until the panes came together. The ceiling was built as a barrel vault; it wasn’t built flat and then vaulted.
Note that this rule applies to compound modifiers. A single word in a similar construction often requires the -ed:
a vaulted ceiling