Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
From an image on opengameart.org shared by rubberduck.
Source Firkin
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'Codogno e il suo territorio nella cronaca e nella storia'', Gio and Giarella Cairo, 1897.
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
White circles connecting on a light gray background.
Source Mark Collins
This is a hot one. Small, sharp and unique.
Source GraphicsWall
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Colorful Floral Background 3 No Black
Source GDJ