Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Dark blue concrete wall with some small dust spots.
Source Atle Mo
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Black And White Floral Pattern Background from PDP.
Source GDJ
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin