I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
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
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda