CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin