On a Windows PC, when you have a document in view to print, make sure the printing settings in the application or program that the document is viewed in, or correct... that is probably where the small size is coming from. Also, try printing one page from a Notepad, to see whether it's just the document or the application that is making the printing small - if not, then you probably have a corrupted printer driver, and will need to replace the printer drivers with a fresh copy - basically to turn Off the printer, remove the printer from the Control Panel - Devices and Printers screen, restart the computer, then re-load or re-download and install the printer drivers afresh.
(If you need details on how to do that,please tell me the model of Canon PIXMA you have, and the Windows version on your PC. And I will instruct you further.)
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