This could be a hippy vintage wallpaper.
Source Tileable Patterns
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
A seamless texture of worn out "cardboard".
Source V. Hartikainen
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
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
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
An alternative colour scheme to the original seamless pattern.
Source Firkin
Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen