“Prints With/Out Pressure: American Relief Prints from the 1940s through the 1960s,” is on view through January 29 at The New York Public Humanities and Social Sciences Library at Fifth Avenue and 42nd Street. The exhibit, featuring 148 prints from the library’s print collection, reveals that artists began to explore and experiment with the relief print in the 1940s, and continued through the 1960s.

To make a relief print, the artist cuts away parts of a matrix – often a wood or linoleum block; the remaining raised surface is inked and the inked image is then transferred to paper. The exhibition’s title, “Prints With/Out Pressure,” implies that while some artists relied on the pressure of a printing press to transfer the ink to paper, others required little equipment – the back of a spoon or the artist’s hand – to transfer the image to paper. Many artists, including Milton Avery and Naum Gabo, capitalized upon hand printing to produce unique impressions or to vary an edition.

Leonard Baskin, Misch Kohn, and Bernard Reder tapped the expressive impact of black and white in their powerful relief prints, as did Irvin Amen in his pared down black and white figures. For Will Barnet, angular arrangements of bold woodcut lines printed in black captured the spirit of quiet domestic scenes. Seong Moy, Antonio Frasconi, Leona Pierce, Karl Schrag, and Adja Yunkers used color to give their figurative or abstract prints dramatic impact.

Vincent Longo, Fred Becker and Robert Conover found in the resistant woodcut a vehicle to communicate a gestural energy in large, abstract relief prints. While most of these artists continued to work with a wood or linoleum block, the exhibition shows that others, like Boris Margo, Harold Paris, Arthur Deshaies, Edmond Casarella and John Ross, utilized new and nontraditional printmaking materials, including celluloid dissolved in acetone, Lucite and cardboard to create a relief matrix.

Until the 1930s most American artists seemed unaware of or indifferent to earlier innovative woodcuts by painters such as Gauguin, Munch and the German Expressionists. But by the end of the 30s, Barnet, Louis Schanker and Werner Drewes discovered that printmaking served their expressive needs and individual styles. The exquisitely crafted wood engravings of Fritz Eichenberg, Lynd Ward and Grace Albee continued to be favored for book illustration, and for prints commissioned by conservative print clubs and societies. But by the middle of the century, a number of artists had begun to explore and exploit the wide range of artistic possibilities and the rich, expressive visual language offered by the relief print.

Many of the prints in “Prints With/Out Pressure” were given by or acquired from the artists themselves; others came from some New York galleries that dealt in contemporary prints. Some were purchased from print clubs and the International Graphic Arts Society, and others came to the library through gifts and bequests from Una Johnson, curator of prints and drawings at the Brooklyn Museum, who (along with the library’s then-print curator, Karl Kup) championed many of these artists through exhibitions, monographs and the highly influential Brooklyn Museum National Print Annual Exhibition.

Among the works on view, documenting the wide range of styles and versatility of the relief print, is Ward’s 1947 wood engraving “Bridges at Echo Bay.” The images of Argentine-born American artist Frasconi, like Ward’s, were closely tied to the physical world, but Frasconi tackled the wood block with bold cuts and slashes not only to describe but to exude energy as in his vividly colored “Boy with Cock.” Frasconi’s approach to the woodcut also captures both physiognomy and personality in his portraits of Einstein and his acerbic caricature of J. Edgar Hoover.

Moy extracts the chaotic energy of the circus in his 1953 “Two Circus Acts in One.” The exhibition also documents how Moy created this abstract color woodcut through a series of progressive proofs.

Schanker used the woodcut to create energized abstractions, such as “Circle Image,” 1952. Leonard Nelson, Drewes and Worden Day found inspiration in the seemingly abstract hieroglyphic notations in Native American art. Adolf Gottlieb also was intrigued by these “primitive” pictographs, which he combined with his interest in Jungian theories in his untitled 1944 color woodcut.

The exhibition also demonstrates how the artist’s choice and use of materials were integral to his or her intent. Albers experimented with three different printing matrices – cork, linoleum and wood – to achieve different textural and spatial effects. Margo realized fluid abstractions through his use of celluloid dissolved in acetone. Schanker and Anne Ryan both used layers of ink, color and black, applied while other layers were still wet, to achieve their desired results.

“Prints with/out Pressure” is on view in the Print and Stokes Galleries, admission is free. For information, 212-869-8089 or www.nypl.org.