Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Prismatic Groovy Concentric Background
Source GDJ
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Original seamless pattern with an Inkscape filter.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Green Background Pattern
Source V. Hartikainen
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
The perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Prismatic Groovy Concentric Background 3
Source GDJ
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Prismatic Floral Background No Black
Source GDJ
A seamless pattern formed from background pattern 102
Source Firkin