Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
Green Background Pattern
Source V. Hartikainen
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Abstract Ellipses Background Grayscale
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
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