Since 1992 Prinz Optics has been developing and producing glass with optical coatings applied by sol-gel dip-coating, a wet chemical coating process which is ideal for the efficient coating of tubes and large flat surfaces. The optical effect is created by interference. Optical filters of this kind can be applied in fields such as lighting, medical and industrial technology and in architecture. The maximum sheet size is 1400 x 1000 mm in glass up to 6 mm thick. For outdoor applications both sides of the filter pane are laminated with uncoated glass, which can if necessary be thermally toughened.