Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A seamless texture of worn out "cardboard".
Source V. Hartikainen
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
An orange vertically striped background pattern. Feel free to download and use this orange background pattern, for example, on the web). It resembles a wallpaper with vertical stripes or something similar to it.
Source V. Hartikainen
Looks like an old rug or a computer chip.
Source Patutin Sergey
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ