Might not be super subtle, but quite original in its form.
Source Alex Smith
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Similar to original, but without gaps in between the arrows. This seamless pattern was created from a rectangular tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
CC0 and seamless wellington boot pattern.
Source SliverKnight
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is a remix of "geometrical pattern 01".
Source Yamachem
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed