Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
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
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
Prismatic Abstract Background Design No Black
Source GDJ
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
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
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin