Black correx board, slightly larger than A5 and 3 cable-ties.

A super lightweight map holder to save you lots of time and folding of maps. Simply make 3 pairs of holes in the board where required and use the cable-ties to attch the board to your stem and handlebars (you can even re-use the cable-ties if you undo them carefully). Now simply pick a couple of the elastic bands up of your drive that the postie leaves behind, to secure the map to the board.