Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Geometric Background 5
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
This one is amazing, truly original. Go use it!
Source Viahorizon
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus