A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
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
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
This one needs to be used in small areas; you can see it repeat.
Source Luca
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Sometimes you just need the simplest thing.
Source Fabricio
Abstract Tiled Background Extended 8
Source GDJ
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.
Source V. Hartikainen
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin