I'm about to order my invites (from Wedding Paper Divas) and at the envelope stage, they give you the option of choosing the envelope with "layered card." The note says "Includes cardstock to layer your cards. *Assembly required." I assume that means you glue your invite to colored cardstock to give it an extra effect? The reason I ask is because our invites actually have a beautiful image on the back of the invite, so I definitely would not want it to be covered by anything. Or do layered cards mean something else? I am probably vastly overthinking all of this...