I constructed a box to hold my plans. It will allow me to display the sheet that I am working on, It will store under the workbench when I need to get it out of the way. I can also easily carry them from shop to house for study.
The box is made from 1/2 inch plywood for the back, 1x2 for the frame (mitered and rabbited for the back and stapled together) and a sheet of plexi glass just lays on top of the plans to keep them clean and flat. I had all the materials laying around the shop so no additional costs.