.I cannot get a borderless print. Works fine in Elements
So in Lightroom open "Page Setup" and choose paper size and borderless in the Printer dialog (as per your printer manual).
Then in the Lr Print Module, Layout Panel- set ALL margins to absolute minimums, and set cell size to absolute maximums.
Note: if aspect ratio of image is different to the Paper aspect ratio (eg. 6x4) then you will get some white border margin unless you check "Zoom to Fill" in the "Image Settings" panel.
thus the problem does not lie with the printer. Moreover the function works correctly in Elements.
The problem is that Lightroom (LR6.3) does not accept the settings from the Canon printer. Do you have any solution?
Do you open the Printer setup dialog in Lightroom for each image you want to print borderless and set the printer as 'borderless' and Paper size? (The printer would not 'remember' settings you may have used for printing from Elements, etc.)
And after setting 'borderless', are you checking LR settings- [Zoom to Fill], and [Layout] Margin sliders at Minimum, Cell Size sliders at maximum?
Why won't the sliders 'move' ? (in any direction??)
Please provide screenshots of your having set the proper paper size and borderless printing in your Canon printer driver as well as your LR paper and border settings.
With specific examples, someone may be able to tell you what is wrong, but all we can do, now, is tell you that it works for us and that the problem must be something on the computer and not in LR.