Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Fix side and a seamless pattern formed from circles.
Source SliverKnight
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
A bit strange this one, but nice at the same time.
Source Diogo Silva
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A set of paper filters. The base texture is generated the same way, only the compositing mode is varied.
Source Lazur URH
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Prismatic Abstract Geometric Background 4
Source GDJ
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal