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
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
A seamless web texture of "green stone".
Source V. Hartikainen
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Black And White Floral Pattern Background Inverse
Source GDJ
Continuing the geometric trend, here is one more.
Source Mike Warner
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
Prismatic Abstract Geometric Background 5
Source GDJ
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin