Matting,   C o n t i n u e d Cutting a mat To cut a mat by hand, use this table: by  hand (Continued) Step 1 Action 2 3 4 5 6 7 8 9 10 11 12 Measure the opening of the frame or determine the overall dimension. Measure the image area you want exposed through the mat. Cut a matboard and a back board the same size as the opening in the frame or the overall desired dimension. On the surface of the mat, lightly mark the dimensions of the mat opening. Place the steel straightedge on the mat surface to guide your blade. Beginning at the corners, cut through the matboard. Remove the unwanted portion of the mat. Using a piece of sandpaper or an emery board, remove jagged or rough  edges. Carefully remove pencil lines with a nonabrasive eraser. Place a piece of tape along the top edge of the image with the sticky side half on the back of the image and half exposed. Carefully position the mat over the image area and press down over the  tape. Put the back board behind the matted image and place in the frame. If you are not framing the matted image, secure the back board to the back of the matboard with double-backed tape. Continued  on  next  page 2-33