An attempt for cleaning up the original image in a few steps.
Source Lazur URH
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor