If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin