A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Lovely pattern with splattered vintage speckles.
Source David Pomfret
Looks like an old wall. I guess that’s it then?
Source Viahorizon
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
To get the tile this is formed from 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
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
From a drawing in 'The Quiver of Love', Walter Crane, 1876
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
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin