An attempt for cleaning up the original image in a few steps.
Source Lazur URH
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Black And White Floral Pattern Background from PDP.
Source GDJ
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Prismatic Geometric Pattern Background 2
Source GDJ
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Gold Triangular Seamless Pattern No Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Just a nice looking textured pattern with faded blue stripes. Well, that's it for today... one background a day, as usual.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ