The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Pattern Background No Black
Source GDJ
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Green Background Pattern
Source V. Hartikainen
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Prismatic Groovy Concentric Background
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Just a nice looking textured pattern with faded blue stripes. Well, that's it for today... one background a day, as usual.
Source V. Hartikainen
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo