Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Classic 45-degree pattern, light version.
Source Luke McDonald
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Abstract Tiled Background Extended 11
Source GDJ
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić