The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
The starting point for this was drawn on the web site steamcoded.org/PolyskelionMaker.svg
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
The classic notebook paper with horizontal stripes.
Source Are Sundnes
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Spice up your next school project with this icon background.
Source Swetha