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
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Someone was asking about how to achieve a fur pattern at #inkscape irc so tried to make a filter on it. Flood filled fractal noises rigged together. May someone find a good use for these.
Source Lazur URH
Have you wondered about how it feels to be buried alive? Here is the pattern for it.
Source Hendrik Lammers
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Fix and cc0 to get the tile this is based on.
Source SliverKnight
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
A version without colours blended together to give a different look.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov