Hi, I've never not used Kodak filters - Polycontrast then Polymax - on Ilford MG and then Oriental Seagull RC papers. This covers about a 30-year period. The filters work in an entirely predictable way in providing appropriate contrast grades at predictable exposure times. Only recently it seems that my most frequently used filters are wearing out, resulting in lesser sharpness. But Kodak filters work great on most brands of VC paper.