A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless pattern formed from background pattern 102
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
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
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective