Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 3
Source GDJ
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton