The Dutch Old Master Rembrandt used a damp-proofing layer on his painting. The Night Watch, which was published in the journal Science, has been found to have a leadimpregnated base layer, which may have been used to protect it from the damp outer wall where it was first mounted. The Kloveniersdoelen guild meeting hall where these musketeers were based was where his painting was originally more than four metres by five metres. Scientists used the Petra III system in Hamburg to investigate a paint sample as part of the project to restore the painting inside a glass box. They compared it with a lead map of the painting that was created using a macro X-ray fluorescence scanner. Rembrandt often used lead white and lead-tin yellow but we found a lot of lead in the dark background, especially at the top. The hypothesis is that he used an impregnation layer containing lead because we clearly saw that the lead was coming before the ground. In the Netherlands it rains, so humidity is high, and at the time there were single brick houses, they had fewer tools to keep the temperature constant.
The physician to English and French royalty made a guide for painters based on developing chemical knowledge. The outer wall of the painting was wet and so the paint areas got disconnected from the canvas. Although we haven't seen it before, Rembrandt suggests that if you have a painting that's going to be hung on an exterior wall, it's better to use a lead-based oil instead of glue.
Even more care needs to be taken to avoid contact with cleaning solvent. The lead reacts with the oil paint to form small crystal balls that fall out of the painting.