Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
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
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Prismatic Abstract Line Art Pattern Background
Source GDJ
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
This is the remix of "Colorful Floral Pattern Background 3" uploaded by "GDJ". Thanks.
Source Yamachem
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Original seamless pattern with an Inkscape filter.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
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 comeback for you: the popular Escheresque, now in black.
Source Patten
A version without colours blended together to give a different look.
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
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A textured orange background pattern with vertical stripes.
Source V. Hartikainen