From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
A version without colours blended together to give a different look.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless Light Background Texture.
Source V. Hartikainen
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow