hey - thanks djblazer! i'm wondering if you can use a layered shader instead of a mix20, as it's only 2 layers. i don't know how many layers you can use on a layered shader though or even if you can use a sss in it.

just managed to get the displacement shader working - i ended up just using my first displacement blinn. everything still needs to be tweaked - especially the bump which is creating some craters - but i'm just glad it's working even if i don't know why...