Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This was formed by distorting an image of a background on Pixabay.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Abstract Tiled Background Extended 12
Source GDJ
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
An alternative colour scheme to the original seamless pattern.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin