CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Prismatic Groovy Concentric Background 5
Source GDJ
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso