Classic vertical lines, in all its subtlety.
Source Cody L
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Sometimes you just need the simplest thing.
Source Fabricio
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin