A comeback for you: the popular Escheresque, now in black.
Source Patten
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
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Abstract Tiled Background Extended 8
Source GDJ
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
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
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
A nice and simple white rotated tile pattern.
Source Another One
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin