This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Found on the ground in french cafe in kunming, Yunnan, china
Source Rejon
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers