The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Prismatic Floral Background No Black
Source GDJ
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
A version without colours blended together to give a different look.
Source Firkin
Colourful background achieved with gradient fills.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin