A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
You may use it as is, or modify it as you like.
Source V. Hartikainen
Fix and cc0 to get the tile this is based on.
Source SliverKnight
An alternative colour scheme for the original background.
Source Firkin
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Prismatic Basic Pattern 2 No Background
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Prismatic Hypnotic Pattern No Background
Source GDJ
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen