This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
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
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Prismatic Snowflakes Pattern No Background
Source GDJ
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
This one has rusty dark brown texture.
Source V. Hartikainen
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
This could be a hippy vintage wallpaper.
Source Tileable Patterns
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin