I bought one set of these tables and my wife and I were so pleased with them we ordered a second set. When it arrived I discovered two of the tables had broken or defective sections of slate. the empty areas had simply been filled in with epoxy. On closer inspection it turned out the same is true of one of the original tables as well. It appears 4D uses slate tailings without regard to completeness or defect. These are sturdy well made items. It is unfortune there is little or no quality control.