It’s big, it’s gradient—and it’s square.
Source Brankic1979
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
Prismatic Floral Background No Black
Source GDJ