<p>New research has revealed that Rembrandt impregnated the canvas for his famous 1642 militia painting ‘The Night Watch’ with a lead-containing substance even before applying the first ground layer. Such lead-based impregnation has never before been observed with Rembrandt or his contemporaries. The discovery, published today in Science Advances, underlines Rembrandt's inventive way of working, in which he did not shy away from using new techniques.</p>