When blending the coatings, ingredients are added to the 100 cu ft (2.8 cu m) ribbon blender in several steps. First, liquid acrylic polymer and water are metered by a pumping system. While the blender is running, 50 lb (23 kg) bags of pigments and fillers, together with various pre-weighed chemicals, are manually dumped into the blender. Next, pre-weighed aggregates are added from self-dumping hoppers using a forklift. Typically, the blend contains about 25% liquids and 75% solids.