From verso of the card: "This illustration shows three methods of preventing fragments of glass flying into a room when the window is damaged by bomb explosion. (A) By two layers of transparent wrapping material gummed all over the inside of the glass. This admits light. (B) By mosquito netting gummed on the glass. (C) By stout paper pasted on the glass. Should the glass be completely shattered, then attach by means of thumbscrews to the inside of the window, a frame (D) in which there are two thicknesses of blanket with 1/2 in. mesh wire netting on each side. Another simple method is represented by a curtain (E) which is let down and fixed round the edges by strips of wood nailed to the window frame."