Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A seamless pattern formed from background pattern 102
Source Firkin
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A free pink background pattern.
Source V. Hartikainen
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Gold Triangular Seamless Pattern No Background
Source GDJ
A white version of the very popular linen pattern.
Source Ant Ekşiler
Neat little photography icon pattern.
Source Hossam Elbialy
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
This background image is great for using in web design or graphic design projects. And don't forget to visit the homepage. I frequently update this resource with fresh tileable backgrounds.
Source V. Hartikainen
This texture looks like old leather. It should look great as a background on web pages.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin