The masks that cover the facial deformities of Erik, the Phantom of the Opera, have ranged from Lon Chaney's 1925 total-face covering (including a strange fabric flap over his mouth) to Claude Rains' 1943 blue-white covering over three-quarters of his face to Andrew Lloyd Webber's version, in which Erik wore a white half-mask.

The changes in COVID-19 masks have been just as wide-ranging. But it seems settled now that N95 and KN95 masks are the most effective for protecting you, and others, from infection.

The problem is that some masks are counterfeit and offer no more than a 20% screen from COVID-19 viruses.

That's the finding of the U.S. National Institute for Occupational Safety and Health (NIOSH). They test masks to make sure they comply with filtration rate standards. In a recent test, more than 6% didn't pass NIOSH inspection.

To be sure they are effective, check for the TC number on N95 masks. The marking will say TC, followed by three numbers and then two numbers and a lot number. The authentic N95s also have a double head strap.

KN95 masks should be marked with GB 2626-2019, then a space, and then KN95. If they don't have that printed on the face of the mask, it is not made to conform to the standard for filtration and protection.