I poked around in some of the menus but did not find anything that would do the job.
Also looked for help, found nothing except this forum, which is okay, but a user manual might be handy for weird stuff like this.
Registration also seems to be a little confused. First visit to confirmation site gets me a 404. Message says contact site administrator. Can't do that unless you are registered.
Also registration says you can't use your nickname as your login ID, but then it proceeds to suggest using my login ID as my nickname, which I went ahead and used. I may never be allowed back in, so I'm telling you all my problems now.
I've been using the SELECT tool to extract large drawings from a multi-page PDF. I have Zoom set to 200% in order to get the detail I need. Problem is that about one half of the saved image is composed of blank blocks.
Maybe there's a way to save selected areas at full resolution. Or maybe I should copy the selected area and paste in another imaging program.

https://docs.kde.org/stable5/en/applica ... menus-file

File → Print... (Ctrl+P)
Prints the file. Use Print to File (PDF) to generate a PDF file or select a range of pages to print only these pages to a new PDF file