From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
It’s big, it’s gradient—and it’s square.
Source Brankic1979
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Light and tiny, just the way you like it.
Source Rohit Arun Rao
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin