A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
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
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
Just the symbols of the signs of the zodiac distributed in a chequer board-like pattern
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Prismatic Abstract Geometric Background 4
Source GDJ
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Might not be super subtle, but quite original in its form.
Source Alex Smith
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
This one needs to be used in small areas; you can see it repeat.
Source Luca
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
A version without colours blended together to give a different look.
Source Firkin
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo