A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki