09-05-2020, 05:30 PM
First thing. Gimp is a raster editor and works in pixels, scaling up or down some of those pixels will be thrown away or will be guessed.
Then there is print resolution. Photographic quality rule of thumb is 300 pixels per inch (ppi) Your high quality 12.25 x 18.375 image might be 882 x 1323 pix @ 72 ppi or 5513 x 3675 pix @ 300 ppi. That has a bigger bearing on quality as anything else. What is the size in pixels of the original image ? What is the size of the image in pixels now?
You can not scale the image with the crop tool could be the scale tool or unified transform from the toolbox. What is the publisher requirements, they should give some guidance. 12.25 x 9.25 at some printing resolution ?
Then there is print resolution. Photographic quality rule of thumb is 300 pixels per inch (ppi) Your high quality 12.25 x 18.375 image might be 882 x 1323 pix @ 72 ppi or 5513 x 3675 pix @ 300 ppi. That has a bigger bearing on quality as anything else. What is the size in pixels of the original image ? What is the size of the image in pixels now?
You can not scale the image with the crop tool could be the scale tool or unified transform from the toolbox. What is the publisher requirements, they should give some guidance. 12.25 x 9.25 at some printing resolution ?