From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Abstract Background Design
Source GDJ
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
A seamless paper background colored in pale yellow.
Source V. Hartikainen
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
"Beige Stone", Tileable Texture.
Source V. Hartikainen
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
I’m guessing this is related to the Sony Vaio? It’s a nice pattern no matter where it’s from.
Source Zigzain