It takes an exhibition as stirring - and yet inconsistent - as Matt Bult's survey of collages at the Paul Thiebaud Gallery to make evident the difficulty of this seemingly demotic technique.

Including works made between 2002 and 2009, Bult's show lets us see his confidence evolving through trial and more trial. Error never really enters into collage, if it does into any art, merely degrees of rightness.

The selection on view shows Bult working with a range of techniques, from the brisk, sure over-painting of a piece such as "Map III" (2007) to the pieces composed entirely of cut, found graphic material, such as "Collage With Musical Notes" (2009) and "Butterflies" (2009).

"Work in Blue" (2009), whose title may double as description and as the artist's note to himself, relies on circular cutouts that set up a kind of visual backbeat. They create keyhole effects that seem to have us looking both at and through a surface punctuated by bright blues and warm browns. The image content of the borrowed material - a close-up here, a deep landscape there - keeps the eye bouncing around in illusionistic space. The occlusion of forms and the circular apertures make me wonder whether a visit to the optometrist inspired this and other, similar compositions on display.

Visitors who know the collage work of Joseph Cornell (1903-1972) will recognize his influence well before seeing a piece in which Bult acknowledges it.

But unlike Cornell's art, Bult's seems driven more by taste than by private obsession. We might sense an admission of tormented competitiveness in Bult's frequent use of details from art reproductions, but his apparent fascination with Jimi Hendrix has not done his collage work much good, on the evidence of what we see here.

Still, visitors will surely leave Bult's show looking forward to his next one.

Pudik at Silverman: Like collage, lowercase-"s" surrealism has persisted well beyond the early 20th century historical movement that gave rise to it. And like collage, surrealism looks easy enough to attract far more practitioners than we might wish. After all, the mind-blowing dissonances in which the Surrealist movement traded have long since migrated from the basement of the collective unconscious into the spotlight of popular spectacle.

So when someone comes along, such as Bruce Conner (1933-2008), who retunes surrealist pictorial tumult so that it feels authentic and relevant again, we notice.

Welcome Yuval Pudik, an artist born in Israel and living in Los Angeles, whose show of drawings at Silverman makes a mighty impression.

In graphite images that mingle details from disparate sources, Pudik symbolizes the colliding mental worlds of militarism, power envy, consumer desire, sexual identity and, perhaps, environmental awareness.

The figure in "Enduring Patiently No. 6" (2009) has it all: royal robes, cleavage, a prosthetic Sten gun, a jet engine growing out of one upraised elbow, a harp growing beneath the other, a face of seaweed and pineapple frond hair.

The knack of making such grotesquerie appear more integrated than arbitrary - more like something witnessed than something concocted - sets Pudik apart among contemporary practitioners of surrealism. I cannot say how he does it, but he sustains the process impressively through the series of works on view.

Pudik cuts out his graphite drawings and mounts the silhouettes on separate sheets so he can postpone deciding how to position his figures. But a series of prints - his first - made at San Francisco's Electric Works, fixes the figures to their grounds and dazzlingly enriches the contrast in the drawings.

Matt Bult: Collages: Through Aug. 22. Paul Thiebaud Gallery, 645 Chestnut St., San Francisco. (415) 434-3055, www.paulthiebaudgallery.com.

Yuval Pudik: Enduring Patiently: Drawings and prints. Through July 30. Silverman Gallery, 804 Sutter St., San Francisco. (415) 255-9508, www.silverman-gallery.com.

E-mail Kenneth Baker at kennethbaker@sfchronicle.com.

This article appeared on page E - 3 of the San Francisco Chronicle