The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
A classic dark tile for a bit of vintage darkness.
Source Listvetra
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
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
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Basic Pattern 2 No Background
Source GDJ
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless Prismatic Geometric Pattern With Background
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ