An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
From a drawing in 'Az Osztrák-Magyar Monarchia irásban és képben', 1885.
Source Firkin
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
The original enhanced with one of Inkscapes's filters.
Source Firkin
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
The texture of this background image has some similarities with leather, and it's colored in a dark brown color. So, if you are looking for a dark brown background image for your website, this may be an option for you.
Source V. Hartikainen
Green Background Pattern
Source V. Hartikainen