Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Abstract Tiled Background Extended 11
Source GDJ
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
This was formed by distorting an image of a background on Pixabay.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin