hungfarlow, 1337, rjkplasticmod, bearubc, thanks for your replies.
I had given up getting any replies on this matter as it was posted in september last, then suddenly four replies, goes to show you just how good this forum is.
Since I raised this post I have been experimenting with them and have been very happy with the results, been using them mainly for fiqure work and applying them by brush, intend to try airbrushing a a latter date.