From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
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
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
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
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
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
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
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
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein