Float glass is one of the most widely used glazings for framing, as it's often the most cost effective. Not suitable for framed work displayed in harsh lighting. 
Available in 2mm, 3mm and 4mm thickness. 

Diffused glass is acid etched, non glare and an ideal glazing for work that will be displayed in a harsh light as it cuts down reflection. 
Not suitable for deep box frames, multi layered mounts over 3mm or frames bigger than A1. It also does not have UV Protection.
Available in 2mm only. 

AR70 is a water white glass that provides a 70% UV Protection to slow the deterioration of any piece of art work, whilst offering an almost invisible and anti-reflective surface for an amazing clarity. 
Available in 2mm and 3mm. 

Art Glass AR99 is a new version of Museum glass which is unmatched when it comes to glazing for picture framing. With its amazing clarity and an even slower rate of deterioration than the UV70, it really is the best in the business. 
Available in 2mm only. 

The Styrene Plastic glazing comes in either clear or diffused depending on requirements. It's a relatively cheap material which is softer than acrylic, but produces a lot of static. It is more often used because of its cost. 
Available in 1.2mm, 1.5mm, 2mm and 3mm. 

Clear cast acrylic is a harder glazing than styrene. Whilst higher in cost, cast acrylic it is ideal for work on a larger scale, as it offers more protection. 
Available in 3mm and 5mm. 

Clear UV Acrylic is the best plastic glazing on offer, with 99% UV protection as the UV absorbers are added to the polymer during the manufacture process. 
Available in 2mm and 3mm.