From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
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
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
Prismatic Floral Background No Black
Source GDJ
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen