Prismatic Triangular Seamless Pattern III With Background
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Might not be super subtle, but quite original in its form.
Source Alex Smith
Abstract Tiled Background Extended 10
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso