Another method involves laboratory burning of a small amount of material that has been soiled and then laundered. The weight of the ashes, plus the weight of the gaseous results of the burning, reveal how much of the dirt remained in the fabric after laundering. A result that is much higher than a clean test sample indicates that a significant amount of dirt was retained in the laundered sample. Naturally, the goal is to come as close to the weight of a clean control sample as possible.