Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
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
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
White handmade paper pattern with small bumps.
Source Marquis
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
You may use it as is, or modify it as you like.
Source V. Hartikainen
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Floral Background No Black
Source GDJ
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski