CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
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
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin