This sounds alot like the science fair display boards. They come in either a variety of colors of corrugated cardboard or what is called foamcore. The foamcore is higher in prce and only comes in white, but would probably be better for use as a small design wall. If I remember correctly the dimensions are 36 x 48 when laid out flat and 24 x 36 when sides are folded to the center. If the sides are set at an angle the board can stand alone for display. These should be available wherever you can buy school or office supplies.