Trouble setting up a new custom page size in gimp.
Found where it is to be done;
Menu: File > Print > opens a dialog with tabs for print destination and setup.
The /Page Setup\ tab has a "Paper size" drop down list. There is a "Custom" selection - but that seems to be bogus (as in: should simply not be there).
How to create new page sizes?
Instead for selecting "Custom" page size, look for "Manage Custom Sizes" a the far bottom of the drop down list.
This opens a dialog where you can manage the current custom page size settings.
Click the + to create a new size, type in a name for it and press TAB (Note ENTER will not work, just reset the name!) and the fill in the measurements.
Make sure to fill in the longer side as "Height" - as the settings here assumes the numbers are for portrait orientation (also note the use of , for decimal separation).
If the measurements should be in mm, inches are 25.4mm (=1" - 12.7, 6.35, 2.54, 1.27mm for 1/2", 1/4", 1/10" and 1/20").
