Building a museum’s permanent collection is an art unto itself.

“It’s not like going to Macy’s,” said Matthew Welch, deputy director and chief curator at the Minneapolis Institute of Art, who has seen many artworks come and go in his nearly 30 years there.

Why do museums collect? By preserving art, they help us understand our world, ensuring that cultural legacies live on.

The very mission of a museum is existential: It’s a reminder of our own mortality, and of civilizations that have come and gone — such as the “Egypt’s Sunken Cities” show now at Mia — but at the same time it reflects our collective past through a multifaceted contemporary lens.

As Welch put it: “We collect the art of our time, but also respond to the interests of our time.”

Historically, art museums were launched by wealthy patrons such as railroad magnate James J. Hill, whose collection of European paintings became a cornerstone for Mia. Gifts make up 92 percent of the museum’s collection, which numbers 93,000 objects, the biggest by far among Minnesota art institutions.

Walker Art Center in Minneapolis has more than 11,500, the University of Minnesota’s Weisman Art Museum has 25,000 and the Minnesota Museum of American Art in St. Paul just over 5,000.

That is a lot of stuff, and only 2 to 5 percent of it is on public view — much like a public library, but without the checkout privileges (although U of M students can borrow certain works from the Weisman).

It takes years to build a good collection — more than a century in the case of Mia, known for its strong collections of Chinese and Japanese art, silver and European paintings. It budgets $5 million to $6 million per year for acquisitions. That might seem like a lot, but quality art is pricey, so the museum tries to be thrifty and tuck aside money in case a must-have work pops up.

“We have to save a war chest!” Welch quipped.

To that end, some museums draw on endowments: investment funds that can provide extra cash for acquisitions. The Walker has one, established by the Weisman’s namesake, the late Frederick Weisman, to buy works for the Minneapolis Sculpture Garden (it paid for the ill-fated “Scaffold”).

The fickle nature of the art market can present a challenge at times.

“The market doesn’t always cooperate,” said Welch. “Just because we want a [Robert] Motherwell doesn’t mean we can go get a Motherwell.”

It’s a chance to ‘live with’ art

The Walker is having a permanent-collection party at the moment. The recently opened exhibition “5 Ways In: Themes From the Permanent Collection” joined two other current shows drawing upon works owned by the center.

That collection was a lure for the Walker’s new executive director, Mary Ceruti, who came from a non-collecting institution, the Sculpture Center in New York.

“A big difference for me is the potential to live with — and study — works over long periods of time,” said Ceruti.

“At a non-collecting institution, shows are on view for 10 to 12 weeks and then the art left the building and we did the next show. It’s exciting for me, and I believe for audiences, to revisit work multiple times and to see it re-contextualized.”

Gifts account for just over half of the Walker collection. Founded by lumber baron T.B. Walker, the museum refocused itself on contemporary art in 1940.

“The Walker commits early [to certain artists], and continues tracking artists through acquisitions,” is how senior visual art curator Siri Engberg explains its collecting strategy.

For example, in 1996 the Walker became the first museum to acquire work by Kara Walker, now ranked among the world’s most important artists.

Unlike encyclopedic art museums such as Mia, the Walker doesn’t aim for what Engberg calls “a checklist collection. We try not to buy works or solicit gifts just for the sake of checking that box.”

By comparison, the Weisman and the Minnesota Museum of American Art (aka the M) have tighter, more thematically focused collections.

The M began collecting in the 1940s. It once had more than 10,000 works, including Asian ceramics, European art and African art, but in the 1990s the museum shifted its focus to American art, particularly from the Midwest.

“Focusing on American identity was a way to distinguish ourselves,” said executive director Kristin Makholm.

The Weisman, opened in 1934 by Hudson Walker, grandson of the Walker’s founder, has strong holdings of ceramics, early 20th-century modernist painting and Korean furniture.

“We believe art is an essential part of the human experience,” said Weisman executive director Lyndel King, who covets a Jackson Pollock painting to round out the museum’s holdings. “It is our responsibility to preserve art.”

Representation is now a goal

Mia, the Walker and the M have worked in recent years to diversify their collections.

“We are really putting effort into finding works by female artists, and persons of color,” said Welch. “The LGBTQ+ community is sort of shockingly underrepresented. That has been a major change in the last five to six years.”

Mia was considered “edgy” in 1954 when it became the first U.S. museum to purchase a work by Austrian-born Expressionist painter Egon Schiele, his 1918 “Portrait of Paris von Gütersloh.” But times have changed.

Makholm noted that any collection that “has grown up in the 20th century — as ours has — has an abundance of art by canonical artists and especially white men,” although the M has a strong collection of work by Ojibwe modernist George Morrison.

The museum recently acquired artist Sonya Clark’s “Triangle Trade” (2014), a thread-on-canvas work that discusses the trade of slaves and goods between Africa, the Caribbean and North America. It was first shown in the M’s 2016 exhibition “Material Mythologies.”

“We do like to acquire works out of exhibitions,” said Makholm. “If it’s good enough to come into a show, it is good enough to come into the collection.”

Saying farewell to a work

Welcoming new artworks is exciting, but nothing lasts forever. Just as death is a part of life, “deaccessioning is a natural part of accessioning,” said Welch.

Deaccessioning is a fancy way of saying that the museum has decided formally that an artwork can leave its permanent collection, as the M did when it auctioned off its non-American works during the 1990s.

This process can take up to a year, and it isn’t nearly as fun as collecting. Curators have to make a case for the removal of a work, based on certain criteria. It might not meet the museum’s standard for quality, for example, or it duplicates something else in the collection.

At Mia, Welch reviews the request, then it’s put in front of a committee of board trustees who also review acquisitions. If a piece is worth is more than $50,000, the entire board must approve. If so, it’s put up for public auction.

Early in its history, Mia accepted entire estates that included porcelain place settings, silver dinnerware, and the like. Since then, the massive museum has gotten serious about cleaning house. While the museum acquired 3,218 objects last year, it also deaccessioned 1,871.

“ ‘Fewer, better’ became my mantra,” commented Welch, who noted that it costs money to store and maintain every work. “The collection can bring you down.”

Or as Marie Kondo might say, if it isn’t bringing the museum joy, it’s got to go.