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
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
It looks very nice I think.
Source V. Hartikainen
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Prismatic Abstract Geometric Background 3
Source GDJ
A seamlessly tileable pink background texture.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin