Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
An alternative colour scheme for the original background.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Retro Circles Background 4 No Black
Source GDJ
Continuing the geometric trend, here is one more.
Source Mike Warner
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin