A comeback for you: the popular Escheresque, now in black.
Source Patten
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Prismatic Floral Background No Black
Source GDJ
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A heavy hitter at 400x400px, but lovely still.
Source Breezi
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
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This is the remix of an OCAL clipart called "Rain on Window" uploaded by "pagarmidna".Thanks.This is a seamless pattern of raindrops.
Source Yamachem
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo