A white version of the very popular linen pattern.
Source Ant Ekşiler
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
Abstract Tiled Background Extended 6
Source GDJ