A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
An alternative colour scheme for the original background.
Source Firkin
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin