A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
A repeating background with wood/straw like texture.
Source V. Hartikainen
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
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
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin