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
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
An alternative colour scheme to the original seamless pattern.
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
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
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
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
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers