The current American standard requires a minimum incision density for western white spruce and Engelmann spruce, but not for any other species. This requirement was based on the available data on the treatability of the western spruces with chromated copper arsenate. This preservative does not penetrate spruce as well as the ammoniacal preservatives. It therefore seemed likely that high-density incising may not be required when using the ammoniacal preservatives. End-matched samples of spruce from six sawmills were single-density- or double-density-incised and commercially treated with one of two preservatives, Ammoniacal Copper Quat (ACQ) or Ammoniacal Copper Citrate (ACcit). Both double-density and single-density-incised lumber from all six mills treated with both preservatives met the AWPA C2 standard. Conventional incision densities of around 6000 incisions per square meter were more than adequate to meet the standard.