A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
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
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Abstract Tiled Background Extended 12
Source GDJ
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
A seamless canvas texture for using as background on websites. Colored in pale tones of brown.
Source V. Hartikainen
Black And White Floral Pattern Background from PDP.
Source GDJ
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
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
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin