I recently got back from a holiday trip. I had my notebook computer with me and had loaded 2013,sp1 on it so I could do a little work in my spare time and also get a feel for the latest release. I have made use of inserting an envelope part into my sub-assemblies in the past as I have found them to be useful in my top level assemblies. (I use the envelope as a subtraction tool to easily create pockets and clearances for my sub-assemblies in my mold designs) I see that the straight-forward process of doing this has been removed from the software. I have figured out a work-around to accomplish what I need to do. However, I wonder if anybody at SW can tell me the logic behind removing this useful functionality. Thank you!