An advanced method of loading material into a gravimetric feeder makes it possible to meter colorant or additive into a plastics processing machine with a degree of accuracy far exceeding that achieved with a volumetric feeder. The feeders are available with throughput capacity of up to 35 lb (16 kg) per hour and can be mounted directly to the throat of most molding machines or extruders. The new loading device transports material to the feeder from a gaylord, drum, or other container. Rather than load continuously, the loader rapidly and completely fills the feeder just once, upon a signal from the feeder controller that the level of color or additive has fallen to precisely 10% of feeder hopper capacity. By tracking and adjusting for actual colorant consumption, the feeders not only provide even greater accuracy and consistency but also make possible detailed documentation of the entire production run.