Glass Types / Picture Protection

The main reason to have glass on a picture is to protect it from physical damage caused by impacts and/or dust and dirt. There are several ways to protect the picture, listed below are the main forms of protection. 

Glass

Glass is the most common and well known, it has been used for at least the last 100 years to protect pictures. The most widely used types of glass in framing are

Standard glass normally 2mm float glass (other thicknesses are available for large pictures). This will be used in most of the framed pictures you have seen, it has good light transmission with few defects.

Non-reflective / Antiglare (etched) glass is the same as standard glass except one or both sides have been acid etched or sand blasted. This scatters the light that hits the glass giving a reduced reflection, however it also gives the picture a matt look and if mounts are used it can give the image a slight haze.

Non-reflective / Antiglare (coated)  glass has a coating applied which helps to eliminate reflections.

Ultra Violet Protection glass helps cut down the U.V. light reaching the picture. U.V. light causes the pigments in the ink to fade and can damage paper

Waterwhite / Colourless glass has many of the impurities removed, this gives you an almost perfect rendition of your image.

Acrylic and perspex

Perspex is usually used where there is a possibility of the picture getting knocked and the glass breaking or where weight is an issue (acrylic is much lighter than glass). Once framed acrylic looks very similar to glass but it is more prone to getting scratched and if dusted can build up a static charge that attracts more dust.

Laminating

Laminating puts a protective film over the picture protecting it from dust and dirt but not from physical impact. This is used on posters or pictures of no commercial value where weight or size is a factor. Various finishes are available.

Many of the above can be combined e.g. you can get etched acrylic or waterwhite glass with an U.V. protective coating.