My building bench is level and covered with a piece of 1/4" thick glass. I will often lay a piece of 1/2" sheetrock on top of the glass, tape or pin the plan to the sheetrock, lay a piece of parchment paper over the part of the plan I am going to build, usually a built up stab or elevator and glue it together. The glue will not stick to the parchment paper and you can see through it. I sometimes use Parchment paper in lieu of velum to trace or draw plans as it is considerably less expensive than velum.
Mike