We're basically used to wearing face coverings while out and about at this point, and you may have noticed that several masks have a small slot to place a filter for extra protection. Adding a filter ...

We're all getting used to wearing face coverings while out and about, and you may have noticed that several masks have a small slot to place a filter for extra protection. Adding a filter in between ...

Melitta, the German maker of the original paper coffee filter, retooled its production to make masks. A director called the filter’s perfect fit over the face “a gift from heaven.” Credit...Daniel ...

Editor’s note: As we will report below, experts agree that face masks with filters — and without — do not replace or relieve the need to wash your hands and practice safe social distancing, and they ...