CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A new one called white wall, not by me this time.
Source Yuji Honzawa
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
Prismatic Triangular Background Design Mark II 5
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Prismatic Abstract Geometric Background 4
Source GDJ
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo