A rectangular platform is formed by folding a flat, two-dimensional unfolded sheet of metal. On the long side of the rectangle, the height of the tray is defined by the angled sides. These are shaped downwards to form feet that prevent the tray adhering itself to flat surfaces.The wider, short sides serve as gripping surfaces and are connected by narrower crosspieces along the long sides. All of the trays (except tray #5) are open on the short sides, which makes them comfortable to grip.
The folds of tray #7.2 and #8 are sealed with two welding seams. In the case of #2, #4 and #5, the fold that forms the grip and sides is riveted to the base plate.