This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Might not be super subtle, but quite original in its form.
Source Alex Smith
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo