I finally got around to buying some silverpoint and have done a few experiments. If you want to see some fine examples of what can be done check out the British Museum website http://britishmuseum.org/ and see what the likes of Leonardo and Raphael produced. Its interesting to use although you have to be fairly patient building it up gradually to achieve the required depth of tone. Of course its non-eraseable so not for the faint hearted and some of my experiments went into the bin after rather too much time invested so the basic drawing has to be pretty good. I quickly learnt to do a faint outline and check that before committing too much time and detail. Having tried various different papers prepared with gouache my favourite so far is an acrylic canvas paper with some texture and I was least keen on watercolour paper.
The first is a study of a Paul Cadmus drawing - he really was an awesome draftsman and definately one of my absolute favourites. Its on a white surface but as is obvious I still havent cracked photographing white paper. The second is from that very famous National Geographic photograph of The Afghan Girl by Steve Curry and is done on a greeny blue tinted gouached paper and both are approximately 9" x 12". Now I just have to watch and see how the silver changes.