robpc wrote:
I am trying to create images 9 x 9 cm but no matter what I do, change print size, change canvas size,scale image I even tried creating a new template 90 x 90mm 300dpi ....
Now first you SHOULD NOT scale down the imagine to print , you give the desired size
in the Printer dialog (if you print for yourself, if not will be done by who print )
About canvas size if you don't need to crop to a different image ratio i can't see why to change
Last 300dpi , now weird as may sound dpi doesn't have any effect on your image file size, that is only a simple info for the printer BUT 300dpi is very very low , you may raise to at least to 900dpi ...
About file size of the image the final file size is much less of the "working size" calculated by Gimp , even if you chose to save in a looseness format (ie .png) to assure high quality the final file size would be much less
Saving as jpg may be more problematic because image loose quality every-time is saved as jpg, this even choosing 100% of quality in the saving setting, jpg have smaller files but that is their only advantage.
Anyway if still may be handled decently by your computer why you worry about the file size of the image to be printed .?
As simple rule of thumb , for images saved in same format and with same dpi (that again is just a info for the printer and doesn't effect file size ) the bigger the file the higher will be the quality