A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Seamless Light Background Texture.
Source V. Hartikainen
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Abstract Tiled Background Extended 6
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning