A limited number of x-rays were taken during the previous conservation campaign in the 1960s. The 1990s project used x-rays more extensively - the whole of two cartoons were x-rayed and the main features of all the others. The x-rays highlight the original lead white paint layer used by Raphael and his studio assistants. Later retouchings in other media, such as pastel, are transparent to x-rays and hence do not show up. As in this x-ray of the head of Christ from the cartoon The Miraculous Draught of Fishes much clearer picture of the condition of the painting can be obtained. A comparison of the 1990s x-rays with those taken in the 1960s shows any changes in condition.