People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
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
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
Abstract Tiled Background Extended 8
Source GDJ
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
The texture of this background image has some similarities with leather, and it's colored in a dark brown color. So, if you are looking for a dark brown background image for your website, this may be an option for you.
Source V. Hartikainen
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin