The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
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
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Embossed lines and squares with subtle highlights.
Source Alex Parker
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
An alternative colour scheme to the original seamless pattern.
Source Firkin
A seamless web texture with illustration of pale color stains on canvas.
Source V. Hartikainen
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec