Lovely pattern with splattered vintage speckles.
Source David Pomfret
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Abstract Tiled Background Extended 12
Source GDJ
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
I have no idea how to describe this one, but it’s light and delicate.
Source JBasoo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz