Remove mats from frames. Set frames and the backs aside.
Flatten fabric (iron it if it is wrinkled) and place mats on top.
Cut the fabric around the mats, leaving about 1 inch of fabric border around the outside.
Snip a hole in the center of the fabric inside the mat. Cut diagonally in an X to each corner. Trim off excess fabric in the center of the mat, leaving about a 1 inch border.
Place craft glue on the edges of the center of the mat and fold the inner fabric over. Glue each piece by pulling taught but don't stretch it too far.
Once the center pieces are glued on, trim off the corners of the outside border.
Add more craft glue to the outer edges of the mats, fold over the fabric, and glue each side down. Press gently to spread out the glue and flatten the fabric.
Allow glue to fully dry. Place photos or prints back in the picture frame by placing them either above or below the fabric mat. Replace the backs of the picture frames, hang, and enjoy!