A bit strange this one, but nice at the same time.
Source Diogo Silva
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Prismatic Groovy Concentric Background 2
Source GDJ
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
This could be a hippy vintage wallpaper.
Source Tileable Patterns
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Polka Dots Mark II 2 No Background
Source GDJ