An abrasive article having a plurality of apertures arranged in a non-uniform distribution pattern, wherein the pattern is spiral or phyllotactic, and in particular those patterns described by the Vogel equation. Also, provided is a back-up pad having a spiral or phyllotactic patterns of air flow paths, such as in the form of open channels. The back-up pad can be specifically adapted to correspond with an abrasive article having a non-uniform distribution pattern. Alternatively, the back-up pad can be used in conjunction with conventional perforated coated abrasives. The abrasive articles having a non-uniform distribution pattern of apertures and the back-up pads can be used together as an abrasive system.