How can I mount 2ft by 4ft fiberboard panels on a wall?
I've used 3M's hook and loop fasteners to hang pictures for years and they have held well. They are sold at a variety of locations. When I use them I stick one part to the picture first. Then I hook the other part to it, peel the film off to expose the sticky side, and carefully press against wall. It helps to have a strip of masking tape that is level and a corner piece of masking tape as guides.