This is a hot one. Small, sharp and unique.
Source GraphicsWall
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
This was formed by distorting an image of a background on Pixabay.
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 #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Abstract Ellipses Background Grayscale
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen