Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
Prismatic Geometric Pattern Background 2
Source GDJ
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Seamless Olive Green Web Background Image
Source V. Hartikainen
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
From an image on opengameart.org shared by rubberduck.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Prismatic Groovy Concentric Background 2
Source GDJ
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf