CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
Prismatic Geometric Pattern Background 2
Source GDJ
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn