thanks for the advice Grymdycche!
I am really keen on the stones, the wooden ones don't seem to appeal to me, I don't know why!
I have a real draw to the sea. I love the stones, the weight of them, and the process of the sea taking them and smoothing them over and throwing them back. (a bit like having a huge bag of runes being tumbled and fired back at you ;
).
I can see what you mean about possibly having to wear eye protection. I don't want to get too industrial, I might try with lightly scoring first, and then painting with nail varnish or something similar.
well let you know how they turn out!