In an object-based vector drawing program (or, for that matter, also a page-layout program), you work with a different conceptual model regarding layers. Basically, a Layer in a raster imaging program is like a clear overlay the size of the whole document, which contains another raster image, the same size, even if portions of it are "transparent." So a raster-image program's document is a stack of one or more same-size, same resolution, same position raster images, which will eventually be "flattened" into a single raster image. An object-based application is and stays a stack of independent objects. Objects are…: Vector-based paths Raster-based images Text objects …and various types of collections or constructs comprised of those basic objects (Groups, Symbols, Compound Paths, Blends, etc.) Much confusion is due to the fact that the so-called Layers Panel in Illustrator is not just a list of Layers, but of all the objects in the document. It should be called the Objects Panel, but it isn't. It has not always been that way. In earlier versions of vector-based drawing programs, the layers panel only listed layers, which are merely user-defined labels for ranges of contiguous objects within the objects stack. (Think of them as "brackets" put around a portion of objects in a list.) That was also nothing like a "Layer" in a raster-imaging program like Photoshop, but the confusion got worse when somewhere along the way, Illustrator got the bright-eyed idea to list all objects individually in the so-called Layers palette, but failed to re-name it to something more appropriate. Most other vector-based drawing programs followed suite in "me, too" manner. So in Photoshop, each Layer is just (or eventually) another same-size, same-resolution, same position raster image superimposed on the base image. In Illustrator each Layer can be a collection of any number of individual independent objects in any combination (vector, raster, text, or other constructs omprised of those), just so long as they are contiguous ("next to" each other) in the overall stack of objects making up the whole document. Therefore, a document can (and often does), for example, contain just one Layer with a kazillion objects of various types "on" it. All those objects are still independent, separate objects. But the ill-named "Layers Panel" lists all of those objects, even if they are all contained in the same Layer. JET
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