From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
A black tile-able background with paper-like texture.
Source V. Hartikainen
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ
This one has rusty dark brown texture.
Source V. Hartikainen
Abstract Ellipses Background Grayscale
Source GDJ
A bit of scratched up grayness. Always good.
Source Dmitry
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin