Might not be super subtle, but quite original in its form.
Source Alex Smith
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
A seamlessly tileable pink background texture.
Source V. Hartikainen
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Prismatic Groovy Concentric Background No Black
Source GDJ
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
The texture of this background image has some similarities with leather, and it's colored in a dark brown color. So, if you are looking for a dark brown background image for your website, this may be an option for you.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin