From an image on opengameart.org shared by rubberduck.
Source Firkin
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The image is a design of blue glass.How about using it as background image?
Source Yamachem
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo