A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
Prismatic Curved Diamond Pattern No Background
Source GDJ
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Prismatic Polyskelion Pattern No Background
Source GDJ
Prismatic Abstract Background Design No Black
Source GDJ
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen