Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
Original seamless pattern with an Inkscape filter.
Source Firkin
Run a restaurant blog? Here you go. Done.
Source Andrijana Jarnjak
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background
Source GDJ
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin