The “skin” can last for more than a day.

One of the first applications, said Dr. Barbara A. Gilchrest, a dermatology professor who is part of the research team, was on undereye bags, a condition that plagues so many middle-aged and older people.

“We wanted something that is elegant, and the ultimate test is right there on your face,” she said. “You really can’t see it. It’s there. It looks normal. We saw that as a very high bar. If you can achieve that you’ve done something impressive.”

(The researchers emphasize that the second skin is significantly different from a product that Living Proof tried to market a few years ago as a cosmetic that could correct undereye bags.)

Those studies included tests on people with undereye bags and those with dry skin on their legs. In one study, participants put second skin on their forearms to see how quickly the skin returned to normal after it was pinched in a suction cup — a test of elasticity. In another study, people were randomly assigned to use second skin or a placebo under their eyes. Trained observers graded the subjects on the appearance of the undereye skin. The product’s durability was tested in volunteers who wore it while running in heat and working up a sweat, while swimming, and while going out in a rainstorm.

One of the important uses, the researchers said, is in treating eczema and the sort of dry skin that comes with aging, with dry itchy patches on the back and legs that keep people up at night, scratching.

“We tell people to pat their skin with a damp washcloth and put on a heavy moisturizer, but that only lasts a short time,” Dr. Gilchrest said. “They end up with greasy goo all over the sheets, and they wake up in the middle of the night, terribly uncomfortable. We need something that was easier to use and didn’t make a mess and stays. Which is what this stuff does.”

Another application of the second skin is to keep drugs like cortisone creams on the skin, Dr. Anderson said. Less than 10 percent of what is applied stays there. “The other 90 percent ends up on your pillowcase or your clothes.”