Now you can remove all but the corner pins from the piece. Put the undermat back on and do what readjusting needs to be done. This is the usual method of mounting cross stitch. Photos are placed under the undermat, positioned then the mat board is lifted, the position marked and double faced ATG tape is run just a hair's breath away from that line. This sticks the mat to the foam core encasing the photo without damaging it.
Some stitchers prefer to lace their needlework to the foam core.
This is done with a very stout sharp needle and quilting thread running the thread back and forth between the sides of the piece on the back. This method takes some practice but is considered to be museum type mounting. It also demands that you have enough fabric to go completely under the mats and around the back of the piece. If you intend to lace your needlework get plenty of fabric to stitch on. Finishing the Framing Now apply ATG tape to the undermat in about the middle of the edges.