Hi Ben 2010/4/14 Ben Goren <ben@xxxxxxxxxxxxxxxx>: > It just occurred to me. Most papers laced with FWA are coated on one side > only. > The back side of the paper is uncoated and has no brighteners. Most sheet-fed offset papers that I encountered have equal spectral properties sidewise and yet contain FWA. And yes, most inkjet papers are probably non-equal, but I don't think FWA content is the only factor. There might be non-FWA whitening agents, drying agents and differing paper structure effecting measurements. Martin Weberg