Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
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
It’s big, it’s gradient—and it’s square.
Source Brankic1979
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
This one is amazing, truly original. Go use it!
Source Viahorizon
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
The image is a design of blue glass.How about using it as background image?
Source Yamachem
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin