A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
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
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
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
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić