Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
A seamless web texture of "green stone".
Source V. Hartikainen
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A seamless texture of worn out "cardboard".
Source V. Hartikainen
Could be paper, could be a Polaroid frame – up to you!
Source Chaos