Thanks for taking the time to respond Night and Alan. I have cleaned all used toppers with soapy water, with no luck. I’m also pretty obsessive with keeping my machine clean and free from splashed grit/swarf. I think the bottom line is the quality of the toppers. I’ll probably go with a Batt with 600 on one side and see if that alleviates the problem. Smaller deep colored stones ~1.5ct or less seem to hide the scratches better as I can use the DLite 3000 more effectively to remove scratches on the smaller sized facets. But I’m probably putting more wear on that laps than it was designed for.