Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
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
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen