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
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
This background image is great for using in web design or graphic design projects. And don't forget to visit the homepage. I frequently update this resource with fresh tileable backgrounds.
Source V. Hartikainen
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein