A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
Seamless Light Background Texture.
Source V. Hartikainen
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
A comeback for you: the popular Escheresque, now in black.
Source Patten
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
Spice up your next school project with this icon background.
Source Swetha
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Prismatic Floral Background No Black
Source GDJ
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee