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
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
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
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
A background pattern with a look of rough fabric.
Source V. Hartikainen
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.
Source Atle Mo
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ