Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Almost like little fish shells, or dragon skin.
Source Graphiste
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
To get the tile this is based on, 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
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin