Slate delves into what it will take to repair the Picasso that billionaire goofball Steve Wynn put his elbow through:
The torn ends of the canvas can probably be lined up, and conservators can identify matching fibers on either side of the rip by inspecting them under a microscope. In general, you can expect the wefts in the fabric–that is, the crosswise yarns of the weave–to split at the site of the impact. The lengthwise warps tend to get stretched out, but they may not break.
(via Kottke)