A 10-minute Metro ride connects two superb exhibitions of American woodcuts, at the Philips Collection and at the Museum of History and Technology.

The Smithsonian exhibit traces woodcut technique from colonial times to its displacement by photoengraving in the 1890s. Transferring photographs and drawings directly to the printing plate certainly saves a vast deal of time and labor, but in the process we have lost much of the texture of line and the discipline of composition that were imposed on the artisan - or artist - who, of necessity, really had to look at his work.

Technicians have supplanted the woodcutter, but the technique is very much alive, as a visit to the Phillips shows. Although Carol Summers, perhaps the most successful contemporary artist of the medium, has almost entirely abandoned the representational tradition, the 55 prints being shown take full advantage of the richness of the woodcut.

"Wood is an inviting medium when compared with other printmaking mediums that require work with metals and chemicals and involve indirect technologies," Summers said in an interview with former Phillips curator Gene Baro.

"Woodcutting offers simplicity and directness . . . The freedom from the laboratory aspect of etching, lithography and screen-printing, the naturalness of a process of cutting, defines the appeal. I earned my living by carpentry in the years before I was able to support myself through printmaking."

With one or two exceptions, which are not included, Summers works entirely in color, and lots of it. The 55 prints shown cover a quarter-century of his effort. He might have been better served by a smaller selection; displayed at narrow spacing, the prints for the most part do not reinforce each other.

Seen serially, preferably Smithsonian first, the two exhibitions are richer than the sum of their parts.