This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Retro Circles Background 4 No Black
Source GDJ