This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Prismatic Triangular Background Design Mark II 5
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
The image depicts a seamless pattern which was made using stripe-like things including borders.I used OCAL cliparts called "Blue Greek Key With Lines Border" uploaded by "GR8DAN" and "daisy border" uploaded by "johnny_automatic".Thanks.
Source Yamachem
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Psychedelic Geometric Background No Black
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
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 background pattern with a look of rough fabric.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin