Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
It looks very nice I think.
Source V. Hartikainen
Plywood Web Background background image for use in web design.
Source V. Hartikainen
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
Sharp but soft triangles in light shades of gray.
Source Pixeden