I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
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
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A seamless web texture of "green stone".
Source V. Hartikainen
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo