Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Zero CC plastic pattern texture, photographed and made by me. CC0 *Note, this texture was on the perfectly smooth surface of a plastic shovel scraper, not sure how to call it. Plz coment if you know what its called.
Source Sojan Janso
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida