Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Just like the black maze, only in light gray. Duh.
Source Peax
Old China with a modern twist, take two.
Source Adam Charlts
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Zero CC tileable hard cover cells, skin like, book texture. 4K, Scanned and made by me CC0
Source Sojan Janso
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen