Hi, thanks for your comments
Paper Fan, First I put a layer of Humbrol gloss varnish (that's because when painting large areas of some types of paper, the water based paint will make the fine fibres of paper to ''stand out'', varnish protects paper from doing so) , then I paint it with Tamiya Grey XF-75. When it's dried I apply a layer of Winsor & Newton Matt UV Varnish, to protect colour from sunlight.