Carbon-14. Carbon-14 dates organic material. For paintings and drawings, this means that we can carbon-date canvas, wood and paper. We can also carbon-date ivory, bone and horn objects. The results are always plus or minus 40 years, which means that there is an 80-year range of accuracy. For example, a piece of canvas carbon-dated to 1900 would have been produced some time between 1860 and 1940.