Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
Prismatic Abstract Line Art Pattern Background
Source GDJ
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
Prismatic Triangular Background Design Mark II 5
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes