The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Abstract Background Design No Black
Source GDJ
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel