From a distance, it resembles a European-style silo mixer in which an integral mixing auger blends all the mortar ingredients. But upon closer inspection, the system's distinctive characteristics become apparent: The large funnel-shaped silo is supported by a frame of legs that straddle a conventional paddle mortar mixer. Patented in 1990, this mortar delivery and dispensing system is a proprietary bulk mortar program. Using a computer-controlled batching process, the producer preblends all dry mortar ingredients, including sand (factory-dried to 0% moisture content) and any color pigments or admixtures. The mix can be based on portland cement and lime, masonry cement, or mortar cement, and is custom-formulated to specification according to the property or proportion method of ASTM C 270 Standard Specification for Mortar for Unit Masonry. Prepackaged in 2,000- or 3,000-pound bulk bags (and wrapped in moisture-resistant outer plastic bags), the preblended mortar is delivered to the jobsite and unloaded by forklift or, if available, the supplier's boom truck.