In grid view, how do I fill the gray space in the cell with the thumbnail?
I need to arrange 12 thumbnails in a row on a small 14 inch notebook display when working with panoramic photography, but there is so much gray space in between the thumbnails in each cell (approximately 30% gray space), making the thumbnails very small and difficult to see. I would like to reduce the gray space to the minimum so that the thumbnail size will increase.
Which Lightroom version are you referring to? You've posted in the Lightroom (cloudy) forum, so assuming that's what you are using have you tried switching to the other grid (the Photo grid, which has virtually zero grey space between the thumbnails).
But if using Classic, I don't believe it's possible to reduce the amount of horizontal grey space used in each grid cell. You can reduce the height of each row by switching from expanded to compact cells (or turning off Grid Extras completely), but that has no effect on cell width so it wouldn't help do what you are wanting to do,