From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
8 by 8 pixels, and just what the title says.
Source pixilated
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
A seamless pattern formed from miutopia mug remixes on a tablecloth.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
There are many carbon patterns, but this one is tiny.
Source Designova
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Prismatic Snowflakes Pattern No Background
Source GDJ
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin