This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.
Source Atle Mo
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
This one needs to be used in small areas; you can see it repeat.
Source Luca
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin
Neat little photography icon pattern.
Source Hossam Elbialy
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ