This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Prismatic Groovy Concentric Background 2
Source GDJ
A black tile-able background with paper-like texture.
Source V. Hartikainen
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
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin