Our Brilliant ground glass focusing screens are available in standard soda-lime glass or borosilicate glass. Standard sizes or custom sizes –made to fit any camera from medium format to ultra large format.
Soda-lime screens provide great quality and excellent focusing with fine detail and great resolution in highlights and shadows.
Borosilicate ground glass focusing screens provide the same excellent focusing traits as soda-lime glass screens, but are a step above. We use borosilicate glass for our premium screens. Borosilicate glass is made of the same material used for lenses, lab ware, telescope mirrors etc. Borosilicate glass can break, but it is tougher and more durable. Soda-lime glass has a blue/green edge color, while borosilicate glass is virtually crystal clear. For more on borosilicate glass: http://en.wikipedia.org/wiki/Borosilicate_glass