CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A comeback for you: the popular Escheresque, now in black.
Source Patten
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Alternative colour scheme to the original.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Original minus the background
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein