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
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Prismatic Hexagonalism Pattern No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
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
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen