From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Geometric triangles seem to be quite hot these days.
Source Pixeden
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin