A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
This is the remix of "Colorful Floral Pattern Background 3" uploaded by "GDJ". Thanks.
Source Yamachem
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Prismatic Polka Dots Mark II No Background
Source GDJ
A pale olive green background with a seamless texture.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes