There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler