Interest in archtops was revived in the 1990s. Archtops had long been expensive instruments, with a level of finish and ornament to match. Boutique luthiers such as Roger Borys and Bob Benedetto brought the aesthetics of the instrument to even greater heights, making them attractive to collectors, and also continuing to innovate in technical design. The Benedetto style of acoustic/electric archtop has itself been copied by luthiers such as Dale Unger and Dana Bourgeois. Most of the accessories (pickguard, bridge, tuner buttons, knobs, etc.) are made of wood (ebony or rosewood) instead of metal and have a clean acoustic look. It is estimated there are nearly 100 archtop guitar luthiers in North America alone.