Conservators examine Epifania, a drawing by Michelangelo Buonarroti

This large cartoon was examined to check that it was safe to travel on loan to another museum. Much of the cartoon's long history could be revealed by shining light across the surface, called 'raking light'. This technique shows up the surface texture, and even the watermarks in the paper (an anchor in a circle in this example).

The raking light also revealed joins in the paper, and a drawing of the joins shows that twenty-six sheets of paper were used. Paper was made by hand at the time Michelangelo drew this image and sheets of such a large size were not available. Small sheets had to be joined together, which must have made large drawings like this one difficult to handle. Not surprisingly, it has suffered a lot of damage in the past, and has been lined with more paper and linen to support creases, tears and missing areas. The layers of paper and linen have caused distortions across the paper surface and tension at the edges where they have been attached to a wooden frame or 'stretcher'. This tension has resulted in the paper splitting in weak areas.

Before the drawing could travel, all the tears and fractures had to be checked to ensure the repairs were secure. Now returned to The British Museum, the cartoon is on display in the air conditioned Prints and Drawings gallery, where the stable humidity reduces the risk of excess tension causing the fractures to worsen.