Studio Goods (Black) Pre-Cut Mat/Presentation Kit: This pre-cut mat/presentation kit starts with a quality white-core, acid free mat board. A sturdy sheet of acid-free foam board backing that is matched to the mat. Both are inserted in a resealable, cystal clear, archival envelope. Great for presenting artwork, storage of artwork or for framing. This mat size is 16"x20" with an 11"x14" mat opening.