A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Lovely pattern with splattered vintage speckles.
Source David Pomfret
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper