The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Prismatic Snowflakes Pattern No Background
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Classic vertical lines, in all its subtlety.
Source Cody L