A comeback for you: the popular Escheresque, now in black.
Source Patten
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
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
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
A free pink background pattern.
Source V. Hartikainen