The classic notebook paper with horizontal stripes.
Source Are Sundnes
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
This one needs to be used in small areas; you can see it repeat.
Source Luca
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Abstract Tiled Background Extended 6
Source GDJ
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Number five from the same submitter, makes my job easy.
Source Dima Shiper
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
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ