A condition in which a print has been affixed to a mount to give it greater strength or to repair minor tears A paper conservator may be required to remove the backing "Laid to cardboard as issued" means that the artist or publisher intended the use of a support See mounted
If you lay something down, you put it down, usually because you have finished using it. Daniel finished the article and laid the newspaper down on his desk She laid down her knife and fork and pushed her plate away
If rules or people in authority lay down what people should do or must do, they officially state what they should or must do. Taxis must conform to the rigorous standards laid down by the police. = set down