Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Lovely pattern with splattered vintage speckles.
Source David Pomfret
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen