Apple - Keep Preview from autoresizing print output

quit the Preview App, enter the following into your Terminal application and then start Preview again. Problem solved!

defaults write com.apple.Preview PVImagePrintingScaleMode 0

to revert this setting, you can use the following command:

defaults delete com.apple.Preview PVImagePrintingScaleMode

I would use Terminal commands slightly different from @Bart's above, although those work just fine.

To disable Preview's default print scaling:

defaults write com.apple.Preview PVImagePrintingScaleMode -bool false

To restore Preview's default print scaling:

defaults write com.apple.Preview PVImagePrintingScaleMode -bool true 

That way, the default stays in Preview's plist, so I don't need some external reminder about that default if I'm poking into it next year when I've forgotten I did this.

Incidentally, the first time I started up Preview after disabling its print scaling, it seemed to hang on launch, so I force-quit and then tried again and it was fine.

Hmm. Tried to edit to make the code lines show...