Geometric triangles seem to be quite hot these days.
Source Pixeden
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
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
Prismatic Basic Pattern 2 No Background
Source GDJ
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Prismatic Abstract Geometric Background 3
Source GDJ
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Prismatic Abstract Background Design
Source GDJ
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless background texture of old cardboard.
Source V. Hartikainen