Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Geometric Background 5
Source GDJ
Prismatic Hypnotic Pattern No Background
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
I scanned a paper coffee cup. You know, in case you need it.
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
Zero CC plastic pattern texture, photographed and made by me. CC0 *Note, this texture was on the perfectly smooth surface of a plastic shovel scraper, not sure how to call it. Plz coment if you know what its called.
Source Sojan Janso
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin