A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Embossed lines and squares with subtle highlights.
Source Alex Parker
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Original minus the background
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic