An explanation of what is going on. From the original post, the request is:
All sorts of ways to do that, I proposed using the built in A4 template which is set at 300 ppi, the rule of thumb setting for printing. That gives an view of how that long image might fit. That involved scaling the image. For printing there is a choice, scale the image yourself or let the printer software do the scaling, up-to-you. I prefer to scale myself.
Back to Gimp. By default the interface is set up in the View menu with Dot-for-Dot ON. One image pixel = one image pixel when the scale is 100%
You can turn Dot-for-Dot off and at 100% scale the image displays at the 'real-life' printed size, according to the ppi set by the image. For this image 96x96 ppi.
see: https://docs.gimp.org/2.10/nl/gimp-view-...r-dot.html
Changing the ppi to 300 ppi, displays the image at 'real-life' size, which might be small.
Scaling the image up to fit A4 @ 300 ppi gets a large image, that at 100% zoom does not fit in the computer monitor, Just the same as a sheet of paper, unless you have one of those large monitors.
Where to find the computer monitor / screen resolution that Gimp uses ? Look in Edit -> Preferences -> Display , where Gimp set the value. You can calibrate it yourself. My laptop, small screen 1920 x 1080 , has a pixel density of 158x158 a more regular monitor might be 96 x 96.
Quote:...Like I have a long rectangular image. It is a photograph of what was a long rectangular piece of paper. Now I want to print it across a number of A4 sheets and I will stick them together.
If I could for instance move a rectangle across the image that represents the size of an A4 sheet
All sorts of ways to do that, I proposed using the built in A4 template which is set at 300 ppi, the rule of thumb setting for printing. That gives an view of how that long image might fit. That involved scaling the image. For printing there is a choice, scale the image yourself or let the printer software do the scaling, up-to-you. I prefer to scale myself.
Back to Gimp. By default the interface is set up in the View menu with Dot-for-Dot ON. One image pixel = one image pixel when the scale is 100%
You can turn Dot-for-Dot off and at 100% scale the image displays at the 'real-life' printed size, according to the ppi set by the image. For this image 96x96 ppi.
see: https://docs.gimp.org/2.10/nl/gimp-view-...r-dot.html
Changing the ppi to 300 ppi, displays the image at 'real-life' size, which might be small.
Scaling the image up to fit A4 @ 300 ppi gets a large image, that at 100% zoom does not fit in the computer monitor, Just the same as a sheet of paper, unless you have one of those large monitors.
Where to find the computer monitor / screen resolution that Gimp uses ? Look in Edit -> Preferences -> Display , where Gimp set the value. You can calibrate it yourself. My laptop, small screen 1920 x 1080 , has a pixel density of 158x158 a more regular monitor might be 96 x 96.