A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Prismatic Polyskelion Pattern No Background
Source GDJ