A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Abstract Background Design
Source GDJ
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Alternative colour scheme for the original floral pattern.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin