Cloth masks have become a staple of our pandemic lives. In the earliest days of COVID-19, we followed online tutorials to sew masks from old T-shirts. Soon, companies of all kinds -from Old Navy to designer Christian Siriano- flooded the market with masks, so we could keep a stash handy whenever we stepped out the door. But the era of the cloth mask may be coming to an end.

As COVID-19 continues to surge, accelerated by the delta variant, several European governments and companies are banning cloth masks, arguing that they are not as effective as medical masks in the midst of the current outbreak.

Confronting new, more transmissible variants of the coronavirus and a winter spike in infections, a number of European countries are beginning to make medical-grade face masks mandatory in the hope that they can slow the spread of the disease.