In carbon-14 dating of pictographs, a low-temperature oxygen plasma coupled with high-vacuum techniques is used to remove carbon-containing material selectively in the paint without contamination from the rock substrate, even if limestone (CaCO₃</sub). In addition to one previously published measurement, two more pictograph samples were analyzed, which are in accord with archaeological inference. A sample of known age charcoal, also processed by this method, matched the control. This technique produces little mass fractionation, the maximum deltacarbon-13 being 0.16per thousand from the untreated sample. Limestone decomposition does not occur during this procedure. Although the technique development is in its infancy, these new results demonstrate that this nondestructive technique has great potential for producing accurate carbon-14 ages.