Agnes Martin at Dia:Beacon

At Dia:Beacon, simplicity commands attention.

On Saturday, April 4, the venerated modern art museum — located at 3 Beekman St. in Beacon, NY — opened an exhibition of works by the middle- to late-20th-century minimalist artist Agnes Martin.

Martin, the Canadian-born New York and New Mexico resident who died in 2004, made the kind of ambiguous abstract art that inspires countless imitators and interpreters.

At first glance, most of the pieces in the new show, “Painting Is Not the Act of Painting,” (on display until June 22) are variations on simple lines and grids painstakingly applied by the artist’s own hand using paint and pencil.

Despite their relative simplicity, it took Martin years of rejecting her own artwork to reach this level of pure abstraction. She would often take knives to paintings she didn’t like, literally slashing work that didn’t live up to her expectations. It wasn’t until she was in her 50s that she began making the work she would become known for.

That evolution is reflected in the exhibition’s 24 works.

Dia:Beacon seems like a perfect place for them. The museum is a monument to simplicity. Even the most complicated pieces are abstractions in their own ways. A straight, unpainted plywood wall with diagonal backing by Donald Judd suggests a room under construction. Michael Heizer’s singular ovoid boulder embedded into a gallery wall strikes unease into visitors.

Subtle grids and softly layered lines by Agnes Martin draw the eye at Dia:BeaconD.H. Callahan

Martin’s pieces feel at home here. In the context of such visual, if not conceptual, simplicity, her art seems louder than it might in almost any other setting. Faint blue and peach stripes gain vibrancy when compared with the all-white canvases of Robert Ryman or the large gray mirrors of Gerhard Richter, both a few rooms away. By comparison, the visibly human-drawn lines of pencil or etched-out paint seem almost complicated, and technically masterful.

It’s enough to make you ponder the name of the exhibition, “Painting Is Not the Act of Painting,” pulled from a quote by Martin: “Painting is not making paintings; it is a development of awareness. And with this awareness, your work changes, but very slowly.”

In a world where studio assistants and fabricators contribute to the output of many artists, Martin relished the act of painting. She painted nearly every day of her adult life. For her, the process was an integral part of the work, and it’s hard to look at these pieces without appreciating her hand.

This repetitive study is also demonstrated across the hall in a gallery dedicated to a single work by Andy Warhol. The piece, “Shadows,” is a study of variations on a single subject. Warhol took photos of shadows in his office and, using a silkscreen process, painted them 102 times on identically sized canvases.

Walking into the room, it may seem like the same image repeated. On closer inspection, the canvases vary widely in color and composition. The work suggests that repetition can produce unexpected forms.

Agnes Martin has become enshrined as one of the leaders of the minimalist movement of the 1960s and ’70s. Her work and artistic philosophies have inspired countless admirers. This exhibition displays a selection of important pieces from nearly 50 years of practice.