High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.
Source V. Hartikainen
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Prismatic Chevrons Pattern 5 With Background
Source GDJ
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A seamless texture of worn out "cardboard".
Source V. Hartikainen
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
A bit of scratched up grayness. Always good.
Source Dmitry
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin