If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
Prismatic Hexagonalist Pattern No Background
Source GDJ
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin