The invention relates to coated products for printing on including a substrate and at least two different coatings having different properties, which comprise a low-coat layer, adjacent to the substrate, preferably pigmented, for printing properties and possibly optical properties, and a different top-coat layer, farther from the substrate, comprising optical pigments for optical effect properties, each coating having a dry coatweight ranging from 0.1 to 12 g/m.sup.2. The invention also concerns a one-pass wet-on-wet multi-layer curtain coating process for producing said coated products suitable for printing on.