Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
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
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin