solvent the preferred mixture is about 5 25 parts of catalyst f or dupont rc 803 curing agent to 100 parts of morton adcote 503a or dupont 49001 polyester resins with cyclohexanone solvent desmodur n 100 an aliphatic isocyanate resin manufactured by mobay chemical corporation pittsburgh pa 15205 may be used as the catalyst or activating agent instead of morton chemicals catalyst f or dupont rc 803 but in which case a smaller amount should be used in the order of two parts of desmodur n 100 to 100 parts of rasin by weight the coating 20 may be applied to the base 15 by any suitable means including the use of a mayer rod a mayer rod is a wire wound doctor rod as known in the art for after the application of an excess of the coating from an applicator roll its use is known in industries to produce recording tapes and reproductive papers blade coating offset coating and fountain coating techniques as well known in the photographic film and paper coating art may similarly be used as well as screen coating in fact one of the most practical arrangements by which el panels can be fabricated consists of screen coating the coatings to be applied should have relatively high viscosities and the evaporation rate of the thinner must be at least an order of magnitudes slower than the thinner in the commercially available resin mix methyl ethyl ketone mek toluene and acetone are thinners which normally could be applied to the resin for silk screening while the evaporative rates of such thinners are too high for practical use it has been found that when cyclohexanone is used as a thinner it permits sufficient working time to coat and prolong screen life in order.