A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Light and tiny, just the way you like it.
Source Rohit Arun Rao
An alternative colour scheme to the original seamless pattern.
Source Firkin
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin