Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
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
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Embossed lines and squares with subtle highlights.
Source Alex Parker
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
The starting point for this was drawn on the web site steamcoded.org/PolyskelionMaker.svg
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen