How do I order alignment holes cut into the stencil to aid in alignment of the stencil over the PCB. For example. I have a project which has 3mm holes in the corners for mounting the finished PCB. When I order the stencil i would like these holes to be cut in the stencil as well. so I can place pins through the stencil and the PCB when I spread the solder paste the SMD holes in the stencil line up with the  pads on the PCB.