From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Prismatic Groovy Concentric Background
Source GDJ
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
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
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall