From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Original minus the background
Source Firkin
Seamless Light Background Texture.
Source V. Hartikainen
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Prismatic Snowflakes Pattern No Background
Source GDJ
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A background pattern with a look of rough fabric.
Source V. Hartikainen
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen