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
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A pale olive green background with a seamless texture.
Source V. Hartikainen
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo