The PLEXIGLAS® Alltop SDP 16 double-skin sheet is a light-transmitting, heat-insulating and very weather-resistant sheet made from acrylic (polymethylmethacrylate, PMMA). It was designed with a particularly wide web spacing of 64 mm for private or factory glazing and greenhouses which require a degree of transparency that is above the normal for double-skin sheets and which only need a minimum of supporting structure at the same time. As opposed to multi-skin sheets type NO DROP1, which carry the proven waterdispersing coating on one side only, Alltop sheets are coated on both sides and within the cavities.