You've got the art, it's fit to be framed, you've chosen the moulding and matting to set it off perfectly – you're good to go. Hold on, back up the bus, you've forgotten the glass!

Not so long ago, there were limited choices for picture frame glazing: float glass, non-glare float glass, and acrylic. The choices were pretty straightforward. Times have changed, and there is now a variety of options available. The purpose of this article is to help consumers sort through the many products on the market, so that they can make the right choice for the right reasons. In this, first of a two-part article, glass options will be explored.

Float glass often has a green tinge caused by iron impurities, blocks less than half of ultraviolet light and, depending on the location of the light source, reflects about 8% of visible light back at you as glare.

Non-glare glass is etched on one side so that reflected light is scattered in different directions rather than bouncing directly back at the viewer. Etching, however, gives the glass a foggy appearance which can obscure the underlying artwork.

In the 1980s a new, very exciting line of glass made just for artworks was marketed by Denglas. Its products included clear float glass which did not distort colour, anti-reflective coating to reduce glare without obscuring the art, and UV filtering coating. Denglas is no longer produced; Tru Vue now makes almost all of the high-end picture framing glass.

• All of their glass is clear float (no coloured tinges).
• Their UV filtering coatings block 99% of UV rays between 300 and 380 nm.
• Anti-reflective coatings on float glass increase UV filtration to 78% (not considered “conservation grade”)
• Anti-reflective coatings show fingerprints easily, so are best handled with gloves and cleaned with microfibre cloths spritzed with rubbing alcohol.
• Available in sheets up to 40 x 60 inches.

Museum Glass: UV filtering coating on one side, and glare reduction coating on both sides.
AR Reflection-Free: Glare reduction coating on both sides.
Conservation Clear: UV filtering coating on one side.
Premium Clear: No coatings. 45% UV blocked, as with regular float glass.
Conservation Reflection Control: UV filtering coating and etched surface on one side.
Reflection Control: Etched surface on one side.

Almost everyone agrees that Museum Glass is a lovely product that is virtually invisible. When cost is not a consideration, it is the product of choice. Its appearance (or lack thereof!) is so good, that many museums and art galleries use it to frame oils and acrylics to protect them from environmental damage without compromising aesthetics. For situations where glare is a problem and budget a concern, Tru Vue makes etched glass. The characteristic fogged appearance increases the further the glass is from the art, so this etched glass is not a good choice for deeply matted items, or shadowboxes.

Previously: The E.J. Hughes Mural: An Expanded Project
Next issue: Acrylic Picture Framing Products