Same classic 45-degree pattern, dark version.
Source Luke McDonald
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
It’s big, it’s gradient—and it’s square.
Source Brankic1979
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
There are many carbon patterns, but this one is tiny.
Source Designova
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
Prismatic Abstract Geometric Background 2
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin