Richard Polsky Art Authentication also has expertise in distinguishing fakes and forgeries by the following artists:

Josef Albers— Pictures of concentric squares comprise almost all known Josef Albers fakes.

Milton Avery — Wide pastiches of color with small figures, painted on paper, is the imagery most commonly associated with Milton Avery counterfeits.

John Chamberlain — Though not plentiful, small-scale assemblages of twisted metal are gradually cropping up. Beware of configurations that are too symmetrical.

Joseph Cornell — Fake boxes tend to be decorative and over-stuffed with objects. They lack the elegant restraint Cornell was known for.

Willem de Kooning — Collectors need to beware of phony abstract female figures — not the classic women from the early 1950s, but the more abstract images from the 1960s.

Richard Diebenkorn — Here we have a situation that is only confined to bogus “Ocean Park” works on paper — never canvases.

Sam Francis — Beware of paintings on paper — including the “Floating Islands” (1950s) and “Blue Balls” (1960s) — that Francis painted at a much later date.

Helen Frankenthaler — In this case, be on the lookout for unstretched and unprimed canvases whose compositions are overly lavish.

Philip Guston — Philip Guston forgeries center around his “Figurative” imagery from the 1970s, rather than paintings from his earlier Abstract Expressionist period.

David Hockney — Beware of questionable images depicting Hockney’s iconic swimming pools. Paintings, colored pencil drawings, and prints are all fair game.

Hans Hofmann— Most Hans Hofmann fakes resemble his classic “Slab” painting from the late 1950s and early 1960s.

Robert Indiana — Predictably, Indiana fakes are always connected to his “Love” icon.

Jasper Johns — Most Johns forgeries depict the American flag. In addition, we have come across fake paintings of numerals.

Franz Kline —Kline’s “high energy” black ink brushstrokes on paper are a minefield. Pay extra attention to works executed on old telephone book pages.

Agnes Martin — Interestingly, Martin fakes are among the most rigorously executed forgeries that come onto the market. Her ethereal lines and pale watercolor brushstrokes are meticulously laid down on canvas (and paper); but her spirit can never be duplicated.

Joan Mitchell — So far, paintings don’t appear to be a problem. The issue is more with pastels that tend to be too colorful (read: decorative).

Robert Motherwell — Hands down, the biggest offender is Motherwell’s signature “Elegy” series, where fakes run the gamut from small studies to major canvases (and everything in-between).

Mel Ramos —While Ramos fakes aren’t plentiful, there are instances of early thickly-painted “Superheroes” making an appearance. Though, oddly enough, you don’t see his trademark female cheesecake nudes counterfeited.

Robert Rauschenberg — Rauschenberg forgeries are confined to his seminal “Combines,” where counterfeiters love to slather paint over found objects attached to wooden boards.

James Rosenquist — While Rosenquist forgeries are uncommon, those that exist relate in some way to his landmark “F-111” painting.

Mark Rothko — Needless to say, Rothko forgers specialize in his mature floating “Cloud” iconography. Strangely enough, you only see three hovering cloud forms; rarely two.

Ed Ruscha — The Ruschas most likely to fall under the forger’s brush are the “Liquid Letter” works from the 1960s and the black and white “Silhouettes” from the 1980s.

Robert Ryman — As the master of the white surface, Ryman counterfeits tend to be lushly pained all-white abstractions.

Wayne Thiebaud — Thiebaud’s prime subjects, specifically cakes and pies where the thick oil paint mimics the frosting and meringue, are the works mostly likely to be forged.

Cy Twombly—  Cy Twombly’s “Chalkboard” series, which resemble white loops on a smudged blackboard, are by far the most commonly forged works.

Tom Wesselmann — Tom Wesselmann’s classic Pop “Great American Nudes” are the only bogus paintings we have come across by the artist.