CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
It’s big, it’s gradient—and it’s square.
Source Brankic1979
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
The perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
Prismatic Abstract Geometric Background 2
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
The tile this is based on 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
A textured orange background pattern with vertical stripes.
Source V. Hartikainen
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs