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
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
A lot of people like the icon patterns, so here’s one for your restaurant blog.
Source Andrijana Jarnjak
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Abstract Tiled Background Extended 6
Source GDJ
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
"Beige Stone", Tileable Texture.
Source V. Hartikainen
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Alternative colour scheme for the original floral pattern.
Source Firkin
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
You know you love wood patterns, so here’s one more.
Source Richard Tabor
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin