Duplicating layers
Much like hiding layers, it can be very useful to duplicate certain layers so you can keep some of the same object attributes as the original (for example, opacity) or for the use of creating design mockups of multiple pages of a website, which have common elements. Also note that when you duplicate a layer it will duplicate all objects, including hidden or locked ones on any sub-layers as well. More information is given in the section Time for action — nesting layers later in this chapter in regard to sub-layers.
