From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
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
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
A white version of the very popular linen pattern.
Source Ant Ekşiler
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
A seamless texture of worn out "cardboard".
Source V. Hartikainen
Prismatic Groovy Concentric Background No Black
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin