Once upon a time, prints were not considered art. Printmaking was -- and still is -- a means of mass-producing an image, often for commercial purposes. So prints were relegated to the status of craft. Such attitudes began to shift in this country when Universal Limited Art Editions opened its workshops in West Islip in 1957. The idea was to encourage collaborations between artist and printer -- sometimes blurring or erasing lines between the two.

You can see examples of most every type of art print -- from woodcuts to silk screens -- at the Heckscher Museum of Art's "Graphic Appeal: Modern Prints From the Collection."

HAPPY 95TH The museum began collecting prints in the 1960s. There were none in the original collection donated by August Heckscher in 1920 to the museum that now bears his name. In observance of the Heckscher's 95th anniversary, all of its shows this year are from the museum's permanent collection.

"Artists were exploring in the '60s," says Heckscher curator Lisa Chalif. "It was a time for experimentation."

Among those experimenting with prints are some of the biggest names in American art at the time -- all represented in this show -- including Romare Bearden, Red Grooms, Roy Lichtenstein and Robert Rauschenberg. They created lithographs, silk screens or serigraphs, a term that was coined largely to distinguish an artist-produced screen print from commercial applications of the same process.

HOW IT'S DONE The earliest techniques were developed in eighth century Japan and emerged in Europe in the 1400s. In woodcuts, reverse images are carved into a block, then dipped in ink and stamped onto paper. Walter Kuhn's "Arts Ball," 1919, a poster-style woodblock print, is part of the Heckscher show. In etchings, which emerged in the 16th century, a metal plate is covered with an acid-resistant coating and a needle exposes a surface that, when dipped in acid, leaves a pattern to be inked and pressed. Childe Hassam's "The Lion Gardiner House, East Hampton," 1920, is a finely detailed example of the process.

Lithography, invented in Germany in 1798, is essentially a painting technique that takes advantage of oil and water not mixing, as in Claes Oldenburg's amusing "Flying Pizza" from his 1964-65 "New York Ten" portfolio. A silk screen, such as Rauschenberg's "Support" or Grooms' colorful "Mango Mango," both from 1973, are created by drawing an image on a fine-mesh screen with undrawn areas blocked by varnish. The image is pushed through the screen onto a print surface.

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Serigraphs, such as Bearden's "Before the First Whistle," 1973, or Robert Dash's "Sagaponack," circa 1980, are produced in a similar way by the artist himself.

A series of six serigraphs by Japanese-born American Risaburo Kimura depicting cities of the world, from Venice to Buenos Aires and New York, beckons like a travel-poster gallery.

"Prints can produce everything from a 3-D effect to the illusion of clouds moving across the sky," says Chalif of the 60 "Graphic Appeal" works. "We've tried to show the range here."

WHAT "Graphic Appeal: Modern Prints From the Collection"

WHEN | WHERE 10 a.m.-5 p.m. Wednesdays-Fridays, until 8:30 p.m. the first Friday of the month, 11 a.m.-5 p.m. weekends through Nov. 29, Heckscher Museum of Art, 2 Prime Ave., Huntington

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ADMISSION $5-$8 (Huntington resident discounts); 631-351-3250, heckscher.org