A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.
Source Atle Mo
Looks like an old rug or a computer chip.
Source Patutin Sergey
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
This could be a hippy vintage wallpaper.
Source Tileable Patterns
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen