Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
This is the remix of "blue wave-seigaiha".The image depicts a seamless pattern of the front upper part of Japanese five yen coin which is used currently.This design represents a rice with ripe golden ears.
Source Yamachem
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Alternative colour scheme to the original.
Source Firkin