Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen