Where are Canon TS3300 scanning profiles located?

I have a Canon TS3300 inkjet printer / scanner. I use the scanner with the excellent NAPS2 PDF scanner software, and I have set up a NAPS profile that uses Native UI . When I scan using this profile, the Native UI from the Canon scanner pops up and asks me to choose a profile: My question: where are these profile stored? I'd like to delete some of the ones I have created, to avoid polluting the list. These are not filenames (an Explorer file search for these files returned nothing) and I couldn't find this information in the manual.

Question by dr_ on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.