A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A floral background formed from numerous clones of flower 117.
Source Firkin
Have you wondered about how it feels to be buried alive? Here is the pattern for it.
Source Hendrik Lammers
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
From a drawing in 'Worsborough; its historical associations and rural attractions', Joseph Wilkinson, 1879.
Source Firkin