This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Black brick wall pattern. Brick your site up!
Source Alex Parker
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav