If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Prismatic Abstract Geometric Background 4
Source GDJ
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
A seamless texture of worn out "cardboard".
Source V. Hartikainen
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
The base gradient edited so now more details are rendered.
Source Lazur URH
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
It’s big, it’s gradient—and it’s square.
Source Brankic1979
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor