As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
8 by 8 pixels, and just what the title says.
Source pixilated
Prismatic Abstract Background Design No Black
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin