To avoid the frosting of eye-glasses by the breath, and to get the upper edge of the mask out of the way of the vision, we have devised the following little improvement:
The mask is made after any desired fashion. Then a piece of lead-foil ½ inch wide and about 4% inches long is slipped into the hem in the upper edge of the mask. The lead is of sufficient weight to retain its shape when molded down over the bridge of the nose on the cheeks. We have been using four-ply lead, such as is used about the Roentgen-ray room for protecting plates. The two thicknesses of the mask should be so folded that there will be no seam above the lead, which would be inclined to fall down or stick out and obscure the vision.
The lead is removed when the masks go to the laundry and reinserted