scans too large

Hi all. Forgive me if this is an old chestnut but I have looked around and can’t see a solution.

when I use Files to scan a document, it is HUGE. A small tag 5 inches by 3 is showing as up to 21MB (one file saved with 2 pages showing back and front.

i can’t find a way to reduce these sizes and can’t email the scans as they add up to over 76MB. I would normally expect a scan of an item this size to be a few hundred k at most. What am I doing wrong?

also sizes vary wildly. Identical tags have been scanned into a range of 4.3 to 21.2 MB.

iPad 12.9 Pro 2nd Gen, iOS 13.3.3.

Thanks

Eddie