A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Abstract Ellipses Background Grayscale
Source GDJ
One week and it's Easter already. Thought I would revisit the decorated egg contest at inkscape community: http://forum.inkscapecommunity.com/index.php?topic=118.0
Source Lazur URH
Prismatic Groovy Concentric Background 3
Source GDJ
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
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
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Original minus the background
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen