A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Prismatic Abstract Geometric Background 3
Source GDJ
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Green Web Background, Seamless tile.
Source V. Hartikainen
A seamless background texture of old cardboard.
Source V. Hartikainen
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. Version with black background.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
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
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
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
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Prismatic Polka Dots Mark II No Background
Source GDJ
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin