A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Prismatic Basic Pattern 2 No Background
Source GDJ
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Prismatic Abstract Background Design
Source GDJ
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
I’m guessing this is related to the Sony Vaio? It’s a nice pattern no matter where it’s from.
Source Zigzain
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper