A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
A browner version of the original weathered fence texture.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
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
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Colorful Floral Background 3 No Black
Source GDJ
Looks like an old rug or a computer chip.
Source Patutin Sergey
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin