Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Looks like an old rug or a computer chip.
Source Patutin Sergey
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Prismatic Abstract Line Art Pattern Background
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective