Might not be super subtle, but quite original in its form.
Source Alex Smith
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
Retro Circles Background 8 No Black
Source GDJ
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Sometimes you just need the simplest thing.
Source Fabricio
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin