Throughout the centuries the preservation of the Shroud faced many difficulties. The most critical moment was in 1532 when a devastating fire broke out in the Sainte Chapelle of the Chambéry Castle and the Linen was damaged by the melted metal of the silver reliquary it was kept in. The white-hot drops had caused a series of symmetric holes (the Linen was folded up). In 1534 the Poor Clares of Chambéry had mended it by applying linen triangular patches on a lining (called Lining of Holland) to strengthen the whole.
In the last decade of the past century cardinal Giovanni Saldarini, the Papal Guardian of the Holy Shroud, set up an international network of scientists to study the best conservation conditions. That commission gave indication of two specific and important works: