Originally posted by l008com:
I want to copy the entire contents of one illustrator file into another illustrator file, but I want to preserve the layers..........
Try this;
1. Ensure all layers are unlocked then hide all layers except for the current one (click each eye icon in the layers palette, or click on the topmost eye icon and drag down)
2. Select all
3. Group
4. Hide the current layer
5. Select next layer
6. Unhide
7. Select all and group
8. Repeat steps 4-8 until every layer is grouped.
9. Unhide all Layers
10. Select All
11. Copy
12. Select next document
13. Hide All Existing Layers (click each eye icon in the layers palette, or click on the topmost eye icon and drag down)
13. Create a new layer
13. Paste and position grouped objects
14. Create '#' new layers (where # is the number of layers in the original document)
15. Select any item using the standard selection tool
16. Drag the little coloured dot, at the right of the current layer in the layers palette, to one of the new layers created in step 14 and then click the eye icon to hide that layer.
17. Repeat from step 15 until all groups have their own layer again.
There is probably a shorter way, but this will work pretty well and shouldn't actually take too long.