Types of Mirror
are many types of mirror, each with varying purpose and design. Here
is a general list of the types of mirror, as well as their function.
Virtually all mirrors for interior use are manufactured by the conveyor,
wet deposition method. Annealed or fully tempered glass is thoroughly
cleaned by the application of cleaners and passing contact with
oscillating scrub brush units. After the glass is cleaned and rinsed, the
surface of the glass is sensitized with a diluted solution of tin
chloride. This surface treatment allows for the deposition of silver.
Silver nitrate is sprayed onto the sensitized surface of the glass along
with other chemical configurations. The final outcome is the formation of
a uniform silver layer on the glass.
Once the silver layer is formed on the
glass, methods to protect the silver layer from oxidation are employed. A
layer of copper is then deposited directly onto the silver. Copper can be
applied in two ways: chemically or galvanically. Recent technological
advances have lead to the development of copper free protective films,
which also prevent silver oxidation.
Once the metal layers are attached to the
glass, they are covered by a protective mirror backing paint. The mirror
backing paint protects the metal layers from corrosion and from mechanical
scratching. The paint can be applied either by passing the glass through a
curtain of paint or by passing glass in contact with a roller paint
coater. There are many mirror backing paint products available from a
number of suppliers. They offer paint systems that are applied as a single
coat or double coat. Both coating systems are effective.
Clear Mirror: Clear glass with a
silver backing, copper and paint. This is the standard mirror used in
the majority of applications. Thicknesses are 3/32, 1/8, 3/16 and 1/4
inch. The largest standard size is 65” x 84” with other sizes available
if custom ordered.
Ultra Clear Mirror: Made with
glass with a reduced iron content. The glass itself does not have the
very slight greenish tinge in found in clear mirror, making it
appropriate for fur salons and all white interiors where absolute
clarity is a must.
Antiqued Mirror: Coatings or
tints are applied to make the mirror look as if it has deteriorated with
Concave Mirror: Glass is curved
inward, and then coated, creating enlarged reflections. Useful as a
Convex Mirror: The glass curves
outward, creating reduced reflections. It can be either decorative or a
useful tool in parking garages or busy corridors to help people see
around the corner.
First-Surface Mirror: Whereas
standard mirror has the reflective coating on the back of the glass,
this coating is on the front. Highly fragile, it is optical mirror for
cameras and kaleidoscopes. Occasionally it is used by designers and
SILVERED TINTED MIRRORS
Tinted mirrors are produced using the methods described above. The silver
coating is applied to one of the various tinted glass substrates available
on the market. Tinted mirrors are generally used in decorative
applications where color and diminished light reflection are desirable.
SILVERED SAFETY MIRRORS
Tempered Mirrors: These are manufactured using fully tempered glass
as the substrate. There are optical characteristics inherent in tempered
mirrors, including roll distortion and the lack of a quality surface for
Laminated Mirrors: These are
manufactured by combining clear glass, either annealed, heat-strengthened
or fully tempered, and mirrored glass.
Safety Backed Mirrors: These are
known as Organically Coated Mirrors in the CPSC 16 CFR 1201 and ANSI Z97.1
standards. These are manufactured by applying a sheet of adhesive backed
polyethylene material to the back of annealed mirrors. The backing
material does not prevent breakage of mirrors, but lessons the potential
of injury on impact by retaining the fragments.
There are two types of non-silvered mirrors: pyrolytic mirrors and
Pyrolytic Mirrors: These are highly
reflective coated glass products with performance characteristics
approaching that of silvered mirrors. This product is promoted for use in
shower doors and other areas where moisture can affect the substrate of
Transparent/Two-way Mirrors: These
are composed of reflective glass products, and as such are not silver
mirrors. Transparent mirrors are manufactured by both the pyrolytic
deposition and vacuum deposition coating processes. Heavy density coatings
are offered on clear and gray tinted glass.
Transparent or two-way mirrors are designed
to permit vision through one direction while giving the appearance of a
standard mirror from the opposite side. Their major application is to
permit undetected observation for study or surveillance in interior
conditions such as learning centers in schools and universities, medical
and psychiatric clinics, and security stations in casinos or high-traffic
The transparent mirrors work by reducing
the visible light transmittance through the glass. To ensure proper
performance the room lighting design and surrounding conditions must be
carefully planned and executed. The glass surface in the subject room must
appear to be standard mirror. In order to achieve this condition, the
coated surface should be toward the subject room and the lighting ratios
tightly controlled. For applications utilizing clear glass, manufacturers
recommend a lighting ratio of 10:1 subject’s side to observer’s side. If
the lighting ratio drops to approximately 5:1, the subject may detect
movement or silhouettes through the mirror. If 10:1 lighting ratios can
not be maintained, a gray transparent mirror should be specified. Lighting
ratios of 5:1 can be successfully used for gray transparent mirror
Design considerations call for bright
contrasting colors in the subject room and dark, non-contrasting colors in
the observer room. Light color surfaces or objects may be noticeable to
the subject. The design of the observation room should also prevent sudden
light ratio changes. Special care must be taken if transparent mirrors are
used on more than one wall.
Metal Mirror: Highly polished
sheets of metal used in areas that require utmost safety and security.
Plastic Mirror: Plastic sheets
are coated with metal to make them reflective. While they have less
optical clarity, are softer and easier to scratch than glass mirrors,
they have usefulness in crafts, displays, children’s furniture and toys.
© GANA Mirror