Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Fix and cc0 to get the tile this is based on.
Source SliverKnight
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Just like the black maze, only in light gray. Duh.
Source Peax
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless background with pink spots.
Source V. Hartikainen
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin