deleted materials swatches how do i get them back!

[Graham Quince]

Hi guys,

My title says it all really. i’d created several materials for a project, then was clearing them out, when i accidently deleted the whole lot. is there a way to restore them???

On another note, i need to create a glass look to part of an object i’m creating (not the whole thing though). does anyone have a preferred method they could suggest.

Graham