Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
An alternative colour scheme to the original seamless pattern.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Retro Circles Background 5 No Black
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
Prismatic Hexagonalism Pattern No Background
Source GDJ
Prismatic Polka Dots Mark II No Background
Source GDJ
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin