OK, thanks for the feedback. I guess I will just do one album at a time and see how the numbers stack up.

Your USB flash drive is probably formatted as FAT32. Aperture libraries can only live on drives formatted as ‘Mac OS Extended’. You need to reformat your USB drive.

Here’s a support article with more info:
http://support.apple.com/kb/HT3509?viewlocale=en_US&locale=en_US

thanks Jim

Continuation from above. In planning for backing up onto a suitably formatted USB drive, I first want to determine the size (Megs/Gigs) of the individual albums. How is this done in Aperture?

One way would be to export the album to your hard drive, then copy it to the USB drive. I don’t think there’s any way in Aperture to determine the size of an album/project/folder.

And in this case if you’re attempting to export as a library, there’s a bunch of overhead files (thumbnails, previews, database files) that will make the library larger than the sum of the original images. No way to predict the size of it.

Tried above “export to folder as a new library” but got this reply - “The library could not be created because the file system of the destination volume is not supported.” I was wanting to backup on to a USB. What is this telling me? I have Aperture 3.1.2. Thanks.

Select that folder and “export folder as a new library “
Select your drive location.
Very simple.