A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Prismatic Curved Diamond Pattern No Background
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin