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 formed from miutopia mug remixes on a tablecloth.
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
Alternative colour scheme to the original.
Source Firkin
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
You know you love wood patterns, so here’s one more.
Source Richard Tabor
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen