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
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
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
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Used a cherry by doctormo to make this seamless pattern
Source Firkin