The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Snowflakes Pattern No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by TheDigitalArtist
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
White handmade paper pattern with small bumps.
Source Marquis
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
A version without colours blended together to give a different look.
Source Firkin
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen