The method used to mount the document or picture in the mat is critical. Although a straightforward procedure, accomplishing it successfully can be tricky, so it's best to leave the task to a trained conservator or professional picture framer. A less complicated, but still archivally sound, alternative is secure the item in the mat with photocorners. High-quality polyester or paper photocorners can be purchased from conservation suppliers. If removal of such adhesives and the stains they cause is possible, the work should only be entrusted to a trained conservator.
Improper treatment can damage items irrevocably, greatly reducing their beauty and value.
Use a good frame that is well-constructed and has mitred joints. The frame should be sturdy enough to support the weight of the object. Glass or acrylic should be used as glazing. Glazing should never touch the work of art. The preservation purpose of a window mat or spacer is to prevent such contact.