A comeback for you: the popular Escheresque, now in black.
Source Patten
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
Background formed from the original with an emboss effect
Source GDJ
Light and tiny, just the way you like it.
Source Rohit Arun Rao
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Prismatic Groovy Concentric Background 3
Source GDJ