When looking at a description of a painting for sale, you might encounter the term "laid-down". This refers to the painting (paper or canvas) having been laid on a firm backing--some kind of board. The question is: has it been permanently attached? Think about the reason for the backing. The painting probably had suffered some kind of damage or deterioration where it needed a stable backing. Thus, it most likely has been fused to the backing. This can negatively affect value. But, if this was the only way the conservator could stabilize the work, it was a necessary step. I discussed this with Richard Kirchner, Director of Preservation and Conservation at the Shelburne Museum in Vermont. He said that, in the end, it's part of the total package. How important is the painting? Was this step absolutely necessary? Are there other paintings like this in superior, untouched condition? Judging a painting's condition history always involves a number of factors like this.