A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A seamless texture of a rough concrete surface.
Source V. Hartikainen
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
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
Prismatic Abstract Geometric Background 3
Source GDJ
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
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
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos