This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
A browner version of the original weathered fence texture.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
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
This one has rusty dark brown texture.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Retro Circles Background 5 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
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Prismatic Groovy Concentric Background 4 No Black
Source GDJ