A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
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 pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
From an image on opengameart.org shared by rubberduck.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
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
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.