Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A repeating background with a look of paper. I have added some changes to PatCreator. Now you can share your designs by submitting them to a new gallery section. Start by clicking Edit with PatCreator above.
Source V. Hartikainen
Number five from the same submitter, makes my job easy.
Source Dima Shiper
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
From an image on opengameart.org shared by rubberduck.
Source Firkin
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
Prismatic Abstract Geometric Background 4
Source GDJ
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Abstract Tiled Background Extended 6
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin