The group is executed in plaster which, according to images obtained using an electronic sweeping microscope, consists of two layers of a different texture, the upper layer more compact than the lower one.

The most unstable areas of the greatest structural complexity were studied using x-rays, which provided information on the different internal structures (pins, nails, screws, wire) present in the work, its state of preservation and the original process of creation.

Through the micro-samples analysed it has been possible to identify areas of different materials that were subsequently applied during previous restorations, such as bees’ wax, synthetic acrylic resins, micro-crystalline wax and animal size, all applied in specific zones. This information has been used to determine the materials required for cleaning the work.