A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev