Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
A seamless pattern formed from a tile made from ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
A seamlessly tileable pink background texture.
Source V. Hartikainen
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Background pattern originally a PNG drawn in Paint.net
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin