Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
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
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo