From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Prismatic Polyskelion Pattern No Background
Source GDJ
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
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 light gray wall or floor (you decide) of concrete.
Source Atle Mo
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Prismatic Groovy Concentric Background 5
Source GDJ
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This was formed by distorting an image of a background on Pixabay.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight