I grind my veneers to .030, I know others that go to .025. Im doing up a bow right now with some figured eucalyptus veneers from a veneer supplier and they are .020. Delicate lil buggers to work with. Real pain in the butt to scarf joint them together for the back. I guess if I had my preference Id do .030, but you can get some really cool packages of veneers through various veneer suppliers. This is the first bow Ive done using those, so will be interesting to see how it goes when I glue it up.