I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Retro Circles Background 5 No Black
Source GDJ
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
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
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Black And White Floral Pattern Background Inverse
Source GDJ
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin