Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Prismatic Abstract Geometric Background 2
Source GDJ
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
Prismatic Groovy Concentric Background No Black
Source GDJ
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Psychedelic Geometric Background No Black
Source GDJ
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy