This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Colorful Floral Background No Black
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Seamless pattern inspired by a drawing on Pixabay. To get the tile this is formed from, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin