The image is a seamless pattern of a fishnet.
Source Yamachem
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Prismatic Curved Diamond Pattern No Background
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ