Automatic methods of calculating canvas thread counts from X-rays of paintings reveal a systematic pattern for warp and weft thread densities that persists along the respective thread directions. These patterns can be used to find paintings that have matching weave patterns, with warp-thread pattern matches more prevalent than weft-thread matches when trying to associate paintings to the same canvas. Exploring the commercial priming process provides a way to interpret canvas matches found from thread counting: when can two paintings that express weave matches be declared to have come from the same roll? In addition, the automatic technique must take into account the variations in thread angles to extract the thread count. The resulting angle maps readily indicate the presence of weak and strong cusping. The weft-thread angle map in particular provides additional insights into the canvas weaving process and can be used to elaborate weave matches.