Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
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
Green Web Background, Seamless tile.
Source V. Hartikainen
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
A seamless background texture of old cardboard.
Source V. Hartikainen
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin