Brad,
The visual marks or pile distortion is largely caused by the compression from the weight of the machine and slapping of the rug against an unforgiving stationary grate on a floor. The grate concept is furnished to give particulates somewhere to go, away from the pile, when vibration of the rug occurs with the belt slapping technique. Our
Wolverine Rug Duster uses belting as straps made of a PVC composite to achieve the best results given the situation. At the end of the day, all machines are tools. It behooves the operator to discern what works best in any given situation. If you use a strap beater/duster, then you may consider putting a pad to cushion compression between the pile of the rug and against the top edges of the grate to eliminate pile distortion. This will allow a little flex during the dusting procedure to eliminate some markings that will resemble the impressions made by the edges of the grates. I hope that helps.