Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
An alternative colour scheme to the original seamless pattern.
Source Firkin
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
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 Canadian horticulturist', 1892
Source Firkin
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
You may use it as is, or modify it as you like.
Source V. Hartikainen
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
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin