Remove margin to see more images

[sergiobd]

I've seen this asked before, but I tweaked my margins and borders in settings to 0, and still I cannot get what I want.
Basically, I'd like to see as many images as possible, by reducing the margins of each image.
See the image attached.


----------------------
| 1 | [XXX] | 2 |
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Basically, I'd like to be able to remove the [XXX] space.

aNY clues?

[xnview]

which thumbnail size do you use?