The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Looks like an old wall. I guess that’s it then?
Source Viahorizon
"Beige Stone", Tileable Texture.
Source V. Hartikainen
Retro Circles Background 7 No Black
Source GDJ
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Prismatic Geometric Pattern Background No Black
Source GDJ
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ