From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Psychedelic Geometric Background No Black
Source GDJ
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Element of beach pattern with background.
Source Rones
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin