Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
CC0 and seamless wellington boot pattern.
Source SliverKnight
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
8 by 8 pixels, and just what the title says.
Source pixilated
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin