A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen