Art Museum employees return to work with a union contract. But bad blood still lingers for some.

For the first time in its storied history, the Philadelphia Museum of Art opened its doors Monday with a fully ratified union contract for 180 workers, ending an often bitter, years-long negotiation process that had culminated in a 19-day strike.

After nearly three weeks of picket lines surrounding the museum, the union and museum management agreed to a tentative deal Friday, just a day before the scheduled opening of a major exhibit of Henri Matisse’s artwork from the 1930s.

Union members on Sunday night voted overwhelmingly in favor of ratifying the contract that secured virtually all of their demands, including four weeks of paid parental leave, 14% raises over three years, a minimum hourly wage hike from $15 to $16.75, and reductions in their health-care costs.

“There are people who have worked here at the museum for more than 20 years and haven’t had raises in that time,” Adam Rizzo, the head of the PMA Union, an affiliate of AFSCME District Council 47, said Monday outside the museum, where dozens of union members gathered to celebrate their victory.

Striking workers returned to work Monday. The picket lines, social media feuds, and allegations of “scab” labor usage that had consumed the building since September gave way to a normal weekday crowd, with dozens queued up to see the new Matisse show when the museum opened at 10 a.m.

Many visitors who had been boycotting the museum in solidarity with the workers expressed a mixture of relief and agitation. Eliza Mann, a member for the last year, said she was delighted that the workers had a contract. “Some of my friends who are members were hesitant about coming during the strike,” Mann said.

Helen Gioulis, a museum member who lives in Center City, came to see the members-only preview of the Matisse exhibit after weeks of refusing to cross the picket line. In her view, museum management took “way too long” to reach a deal with the union — and in doing so tarred the PMA’s reputation.

“This is a world-class art museum and you need to pay living wages,” Gioulis said. “They’re not looking for mansions in the sky.”

» READ MORE: Art museum staffers ratify first contract, look forward to returning to work

A veteran tour guide at the museum, who asked not to be named in order to speak freely on the internal mood, said a large contingent of guides had also been picketing the museum in solidarity. Visitor volume was “cut in half” for the duration of the strike, said Rizzo, citing internal emails from management that were accidentally sent to a union representative. Senior museum personnel helped process admission tickets due to staff shortages, three union members said.

Criticism also extended to the museum’s new director Sasha Suda, who took command of the PMA in September but, in a baffling move to many, stayed out of the negotiation process. During the strike, the union made her a regular target over her lack of engagement, at one point hanging a large canvas banner that asked “Where in the world is Sasha Suda?” outside the museum’s north entrance.

“The new museum director was in a unique position, and she should have taken a close look at the city to see what it would tolerate,” Gioulis said, nodding to Philadelphia’s reputation as a union-friendly town.

Suda called the contract agreement “a partnership between the museum, the city, and the union.” Some museum personnel credited elected officials for helping broker an agreement as tensions escalated.

Some union personnel said management had mistakenly anticipated that the picket lines would fall early on. Instead, the museum found itself backed into a corner as it tried to set up a major exhibition of French modernist works being flown to Philly from overseas.

With museum installers firmly on strike, the union blasted management for hiring “scabs” — or nonunion laborers — to hang the exhibit. But it was the optics of opening the Matisse exhibit to members this weekend amid a robust union protest that pushed the negotiations in their favor, some said.

“They didn’t want us out here [striking] on Saturday for the Matisse opening,” Rizzo said.

» READ MORE: After a long strike, Art Museum director Sasha Suda talks about hope, healing, and getting to know Philly

Despite the union’s victory, bad blood still simmered for some.

During the strike, management locked the email accounts for most of the striking workers, deactivated their building badges, and temporarily froze use of the parking garage, union organizers said. Juliet Vinegra, a project manager at the museum’s library and archives who also organized with the union, said some sympathetic supervisors were “held hostage” and couldn’t show support for the union, as the museum worked to “pretend everything was normal.”

The museum also struggled to quell ballooning criticism on social media from elected officials and union supporters who grew irritated with the seemingly intractable negotiations. (At one point, the museum shut down comments on its Twitter account, citing “profane language.”)

Vinegra said she hoped the union contract — particularly with its parental leave policy and concessions around health-care costs — could help improve working conditions for nonunion personnel, too. But that might take time.

Museum management invited staff to an “ice cream social” Monday in the vaulted, Frank Gehry-designed hallways that run through the base of the museum.

Around 1 p.m., well over a hundred coworkers milled about and chatted over ice cream sandwiches, though there didn’t appear to be any big speeches from either management or union reps.

“There was no ‘congratulations,’” Vinegra said of the tenor between some managers and union members.

Suda declined an interview with The Inquirer as she left the ice cream social.

Tucked under her left arm was a large folded canvas banner — the union’s sign asking about her whereabouts. Several people present at the event confirmed the director had reportedly asked the union if she could take it home.

“I got the sign,” Suda told a reporter as she walked away.

Staff writer Peter Dobrin contributed to this article.