When I work in the hospital I frequently carry around a small stack of laminated cards on a binder ring with hospital protocols/algorithms and other stuff I might need to look up as a quick reference. I call it my peripheral brain. I'm interested in creating my own specialty-specific cards and looking into my options for laminating. I want to make 4" x 6" sized cards that are sturdy (think of the laminated menus at restaurants as an example). Short of going to Staples or Office Depot, how can I do this on the cheap?