Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Geometric triangles seem to be quite hot these days.
Source Pixeden
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Black And White Floral Pattern Background Inverse
Source GDJ
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by TheDigitalArtist
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso