That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Retro Circles Background 7 No Black
Source GDJ
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A seamless web texture of "green stone".
Source V. Hartikainen
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
A seamless web background with texture of aged grid paper.
Source V. Hartikainen