Sort of reminds me of those old house wallpapers.
Source Tish
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
A seamless texture of worn out "cardboard".
Source V. Hartikainen
Abstract Ellipses Background Grayscale
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
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