The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is the remix of "Colorful Floral Pattern Background 3" uploaded by "GDJ". Thanks.
Source Yamachem
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Snowflakes Pattern No Background
Source GDJ
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
White circles connecting on a light gray background.
Source Mark Collins
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A browner version of the original weathered fence texture.
Source Firkin