A heavy hitter at 400x400px, but lovely still.
Source Breezi
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Might not be super subtle, but quite original in its form.
Source Alex Smith