A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
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
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A cute x, if you need that sort of thing.
Source Juan Scrocchi
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Prismatic Abstract Background Design
Source GDJ