A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
Prismatic Abstract Geometric Background 4
Source GDJ
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin