The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf