Glazing
The options of glazing are multiplying. To help simplify matters it is easiest to break the options down and down.
There are two main glazing materials, glass and acrylic. Both have very useful features and it is a matter of picking the right one for the job.
Glass now comes in two main categories, float and coated or specialist glass.
Float glass now subdivides between standard glass, the one that looks green on edge, and water-white glass which looks clear on edge. The choice here is straightforward, the only deciding factor being price.
Glass
Coated glass is more nuanced. The coating also comes in two functions, UV filtration and anti-reflective.
Ordinary float glass has an intrinsic 70% UV filter but 92% and 99% filters are available. 99% is regarded as Conservation grade and should be used for original works, valuable prints and anything that might suffer fading. Fabrics are the most common victims in this area.
Anti-reflective (AR) glass can be invisible when hung carefully. The glass is completely smooth, not the acid-etched “non-reflective” glass, which means it will reflect under harsh lighting conditions.
Acrylic
Or Pespex as it used to be universally known. Perspex is in fact a trade name for a make of acrylic.
The primary function of acrylic is its shatter-proof quality which makes it a legal requirement in some situations, eg exposed public sites, schools, libraries etc. Its other function is its lightness for use with very large glazing projects.
This has become the glazing of choice in many of the world’s greatest galleries, the Rijksmuseum, the Uffizi, the Tate et al, particularly for pictures in transit. Unsurprisingly, it is extremely expensive but under certain circumstances it might be the correct option.
