A pale olive green background with a seamless texture.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A floral background formed from numerous clones of flower 117.
Source Firkin
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin