This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
A heavy hitter at 400x400px, but lovely still.
Source Breezi
A nice and simple white rotated tile pattern.
Source Another One
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Prismatic Triangular Background Design Mark II 5
Source GDJ
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A version without colours blended together to give a different look.
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight