>>> Did you know you could be missing EP/store content stencils? <<<

Anette, I think after you initially download all of the objects you want, you could put them all on one large lot, say, 40x40 or bigger, depending on how many stencils you want to back up, and just back up that lot instead of the 100 individual object downloads.

Also, I am not 100% sure but stencils "may" be part of the "UserPresets". I know saved patterns are. So if you back that file up (it should be in your core Sims 3 folder), that might be useful too.