Picture Frame Inner Workings
Hinging and adhesives
Hinging an image must be done carefully to be sure the sticky parts don't somehow end up sticking to the artwork. Probably the easiest way to look at it is as a step-by-step process.
Attach the Mat
Place your mat, front surface down, so that the top is touching the top of the mounting board. Place a strip of acid-free tape along this seam, on the mat and on the board. The mat should now be able to be flipped over and end up resting on top of the mounting board.
Position Your Artwork
With your artwork face down, on a clear work surface, secure 2 strips of acid-free tape (more for a larger piece) with half on and half off. Now position the image face-up on the backing and test that it's centered by slowly lowering the mat and readjusting as necessary. Note to use a tape that is weaker than the paper the artwork is on. This way, if any pulling or stress were to occur to the artwork, the tape would rip and release before the piece does.
Adhere Your Artwork
When the work is properly positioned, attach 2 strips of acid-free tape exactly across the pieces still exposed. The artwork is now secure and centered in the opening of the mat. Always hinge your piece at the top, leaving the sides and bottom to hang freely. Place the mat and put light pressure where the tape is. You have successfully hinged and adhered artwork behind a mat board.
Picture Frame Sealing
Frames need sealing on the back for a reason. The backing, commonly made of paper and called a 'dust cover', is used to keep bugs, dust and dirt out.
There are a few options as to the type of seal. Sometimes it depends on the material the frame is made of and sometimes it is your personal preference. Note that the backs of metal frames are impossible to seal because of the nature of the material.
Picture Framing Paper
A double-sided adhesive is applied around the perimeter of the back of the frame. Craft paper is then stretched and pressed to the tape, and the sides are trimmed off with a razor blade, or rubbed off with sandpaper. This technique is the most common in North America.
Picture Frame Tape Backing
A thick strip of brown, black or white tape is applied around the perimeter of the back of the frame. This seals the gap between the frame and the backing board, and is quite a durable option. This technique is most common in Europe.