[abrogard]

Thanks for that. I'm not sure I totally comprehend. But I've been having thoughts myself, how about this:

I think maybe I could put 'zip' as the author?

Then they would all be put into that author's folder in the calibre folder?

Then I could copy that to elsewhere? And I'd have all the zips. And I think calibre would read that folder and bring them back into a new calibre library when I want?

so I could delete the original calibre copies then and there i am with a zip free library and a 'nothing but zips' library. two of them. what i want.

It would be great if we had a reserved character or word to prepend that would cause the books to be put into this special folder meant for this purpose. a working 'temp' folder.

And then we could prepend any author name with this reserved char or word and that would cause the books to be put in that folder just so's we could copy them out of it.

A partner function could remove that char or word.

So I could sort on 'zip' - I get about 1000 files currently when I do that - and bulk edit 'author' to (say) " !* temp *! old author string " and they'd get filed in a 'temp' author name folder for me. Bit of clumsy demo to try show what I mean. Actually we'd only need the escape char or word. Perhaps that one I invented there: " !* " Any author string starting with that would cause immediate allocation to this 'temp' folder.
So an original string 'old author' could become ' !* old author ' ( with or without the space ) and that would do it.

I'd go for a mod like that. Would you?