A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one has rusty dark brown texture.
Source V. Hartikainen
Colorful Floral Background No Black
Source GDJ
Prismatic Abstract Background Design
Source GDJ
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
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
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
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
Prismatic Groovy Concentric Background 2 No Black
Source GDJ