Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
From a drawing in 'Codogno e il suo territorio nella cronaca e nella storia'', Gio and Giarella Cairo, 1897.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
A white version of the very popular linen pattern.
Source Ant Ekşiler
Prismatic Groovy Concentric Background 2
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This one is amazing, truly original. Go use it!
Source Viahorizon