A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Prismatic Hexagonalism Pattern No Background
Source GDJ
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Psychedelic Geometric Background No Black
Source GDJ
This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
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
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
A version without colours blended together to give a different look.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin