Perfect mats begin with perfectly squared matboards. It is important to begin with a squared matboard in order to cut squared mats with parallel borders.
Most matboards are available in the standard 32” x 40” size. But the actual size of the board will probably be a fraction larger to allow for changes in humidity during shipping and storage. A full sheet of matboard may be squared by trimming off the excess, creating a true 32” x 40” board. This is a valuable first step, before cutting the matboard to the size needed for the mat.
Depending upon the style of mat cutter, a full sheet of matboard may not fit in the machine. Matboards may have to be manually cut to a smaller size before they can be used. Check the instructions that come with the cutter—they should state the maximum size of board the machine will accommodate.
Once the board is squared, and trimmed to a smaller size if necessary for the mat cutter, the next step is to cut the board to the outside dimensions of the mat—this is called “blanking” the board.
Pull the straight cutter towards you to trim boards.