A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
This one needs to be used in small areas; you can see it repeat.
Source Luca
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
The original enhanced with one of Inkscapes's filters.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Embossed lines and squares with subtle highlights.
Source Alex Parker
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf