I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Element of beach pattern with background.
Source Rones
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
This one has rusty dark brown texture.
Source V. Hartikainen
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
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
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski