Sort of reminds me of those old house wallpapers.
Source Tish
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
This background image is great for using in web design or graphic design projects. And don't forget to visit the homepage. I frequently update this resource with fresh tileable backgrounds.
Source V. Hartikainen
The tile can be had by selecting the rectangle in Inkscape and using shift+alt+i. Remixed from a drawing in 'Flowers of Song', Frederick Weatherly, 1895.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
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
This texture looks like old leather. It should look great as a background on web pages.
Source V. Hartikainen