A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 3
Source GDJ
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin