Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Almost like little fish shells, or dragon skin.
Source Graphiste
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Might not be super subtle, but quite original in its form.
Source Alex Smith
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