Antique mirrors have a softened patina that reflects light more subtly than a new mirror. You can replicate the romantic luster of an antique mirror using eglomise, a glass-gilding technique popularized in the eighteenth century. In eglomise, gold or silver leaf is applied to the reverse side of a glass object. To create her faux-antique mirror, Martha applies silver leaf to the back of a pane of glass, which she inserts into a picture frame.
To make your own silver-leaf mirror, use glass from a picture frame, or have a glazier cut you a piece to fit a favorite frame. Silver leaf, sold in booklets of 3-by-3-inch squares, is easy to work with but very delicate -- one thousand stacked sheets equal the thickness of a nickel. For best results, work in a draft-free room; do not get the silver-leaf booklet wet; and, because it will dissolve, do not pick up silver leaf with your hands -- use a gilder's tip brush instead.
The sizing used to adhere the silver leaf to the glass is made from a mixture of gelatin and water. Martha uses two or three diamond sections of a gelatin sheet, but you can substitute one teaspoon of unflavored gelatin granules. Be sure to use distilled water in your sizing, as it contains no minerals or contaminants that could react with the silver.