Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Colour version of the original pattern.
Source Firkin
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A seamless web texture of "green stone".
Source V. Hartikainen
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin