A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Prismatic Snowflakes Pattern No Background
Source GDJ
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
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
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Pattern formed from simple shapes. Black version.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett