Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
CC0 and seamless wellington boot pattern.
Source SliverKnight
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Might not be super subtle, but quite original in its form.
Source Alex Smith
Abstract Tiled Background Extended 6
Source GDJ
Someone was asking about how to achieve a fur pattern at #inkscape irc so tried to make a filter on it. Flood filled fractal noises rigged together. May someone find a good use for these.
Source Lazur URH
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Colorful Floral Background No Black
Source GDJ