An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
White handmade paper pattern with small bumps.
Source Marquis
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Prismatic Snowflakes Pattern No Background
Source GDJ
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
Prismatic Hypnotic Pattern No Background
Source GDJ
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin