Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
The name is totally random, but hey, it sounds good.
Source Atle Mo
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo