Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Embossed lines and squares with subtle highlights.
Source Alex Parker
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
There are many carbon patterns, but this one is tiny.
Source Designova
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Prismatic Geometric Pattern Background No Black
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Looks like an old rug or a computer chip.
Source Patutin Sergey
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen