MEXICALI, Mexico — Ever since President Trump started talking about building a wall along the U.S.-Mexico border, he’s promised it'd be not only big but also beautiful. And now the Department of Defense has around 100 active-duty Army troops down at the border working to deliver on Trump’s promise: They're painting a 1-mile stretch of the wall along the Calexico, California, border.

Customs and Border Protection says the main aim of the paint job is to improve the aesthetic appearance of the wall, but there can be other benefits if you're trying to, say, thwart migrant crossings: After another part of the wall, in Tucson, was painted white, it became harder to climb and harder for climbers wearing camouflage to avoid detection. But President Trump reportedly wants the wall painted black so it gets hotter during the day, and therefore more difficult to climb. That's the color on the rollers in Calexico. (Besides the heat deterrent, the DOD said the paint creates a slickness that makes it hard to scale.)

A CBP official told VICE News the job is expected to cost $150,000 in materials and equipment, and that it’s expected to be completed within a month.

VICE News didn't get permission to embed with American troops to watch paint dry, but there are two sides to every big, beautiful wall. So we watched from the Mexico side.

Cover image: VICE News asks members of the U.S. Army assigned with painting the Calexico border wall with Mexico, what they think of their latest assignment. (VICE News/Ani Ucar)