Concave mirrors make us look wider and shorter. Convex mirrors make us look thinner and taller. They both have their uses, such as in photography and medical imaging, but they do not belong in our homes. As nice as it may sound to look thinner, it’s counterproductive if we select clothing that is, in reality, not flattering at all. A completely flat mirror gives a true reflection. The slightest curve one way or the other gives a distorted image.
There are three factors you need to look into when assessing the glass in a mirror:
Glass Quality
The quality of the glass depends on how it is manufactured and how pure the raw material used was. High-quality glass has no inconsistencies in its makeup and will not distort a reflection.
Test to see if the glass has a flat surface. Pick up an item and examine it. Then look at it in a mirror. If the reflected image is not distorted, the glass quality is good.
Mirror Thickness
Typically, mirrors are 1/8-inch, 3/16-inch, or 1/4-inch thick (.031cm, .047cm, .063cm). High-quality glass is 1/4-inch thick. Thicker mirrors are much less likely to distort the reflection. Thinner mirrors, even if they appear fine in the showroom, will warp over time.
Mirror Silvering
The mirror should have a high-quality, thick coating of silvering—the coating, usually silver nitrate and other chemical compounds, on the back of the glass. That is what makes the glass reflective. There should be several coats of silvering, finished with a sealer to prevent tarnishing.