A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Spice up your next school project with this icon background.
Source Swetha
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
This one needs to be used in small areas; you can see it repeat.
Source Luca
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin