This is a hot one. Small, sharp and unique.
Source GraphicsWall
A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Sharp but soft triangles in light shades of gray.
Source Pixeden
CC0 and seamless wellington boot pattern.
Source SliverKnight
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
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
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern formed from background pattern 102
Source Firkin
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick