Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
A free background pattern with abstract green tiles.
Source V. Hartikainen
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
A blue background wallpaper for websites. It has a seamless texture with vertical stripes. It looks quite nice not only when using as a tiled background on websites, but also on computer desktops.
Source V. Hartikainen
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Prismatic Abstract Geometric Background 3
Source GDJ
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
A comeback for you: the popular Escheresque, now in black.
Source Patten