Class 'C' is a high performance material. The initial brightness (measured at 2 minutes after removal of the excitation light source) is 3 times higher than Class 'B' and the time to the threshold of visibility is twice as long and set at over 1800 minutes. Have a look at our range of self adhesive vinyl and rigid board that fall into the Class 'C' category and call us on 01702 233380 or 07808 774321 to discuss your needs.