Might not be super subtle, but quite original in its form.
Source Alex Smith
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Prismatic Triangular Background Design Mark II 5
Source GDJ
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Geometric triangles seem to be quite hot these days.
Source Pixeden