From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A bit strange this one, but nice at the same time.
Source Diogo Silva
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
You may use it as is, or modify it as you like.
Source V. Hartikainen
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
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 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