Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Alternative colour scheme. 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
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
The classic notebook paper with horizontal stripes.
Source Are Sundnes
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
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
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
There are many carbon patterns, but this one is tiny.
Source Designova
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
A repeating graphic with ancient pattern. I came up with this name/title at last minute, so you may find that there is very little of ancientness in this pattern after all.
Source V. Hartikainen