back slip, spacer between art care foam and print no mount just 2ply
2 ply for back of presentation matt when lightness is critical or budget of client
Yes 4ply with 4ply all the time for personal work and clients with larger budgets.

Quote Originally Posted by PVia View Post

Excuse my ignorance...what's a back slip? The backing/mounting board?

And you use 2 ply for the back of a presentation mat?

So you never do 4 ply back with 4 ply mat?