Green Background Pattern
Source V. Hartikainen
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A comeback for you: the popular Escheresque, now in black.
Source Patten
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
Fix and cc0 to get the tile this is based on.
Source SliverKnight
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
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
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Psychedelic Geometric Background No Black
Source GDJ
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin