Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Abstract Tiled Background Extended 8
Source GDJ
Prismatic Abstract Geometric Background 2
Source GDJ
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
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
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Abstract Ellipses Background Grayscale
Source GDJ
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen