This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Prismatic Geometric Pattern Background No Black
Source GDJ
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Sharp pixel pattern, just like the good old days.
Source Paridhi
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Polyskelion Pattern No Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Heavily remixed from a drawing in 'Barbara Leybourne; a story of eighty years ago', Sarah Hamer, 1889.
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sharp but soft triangles in light shades of gray.
Source Pixeden
Prismatic Triangular Background Design Mark II 5
Source GDJ
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Prismatic Abstract Geometric Background 4
Source GDJ