From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Prismatic Floral Background No Black
Source GDJ
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
This background texture resembles stone. It may be used as a background on web pages or on some of their html elements (header, borders, menu bar, etc.). Just modify it for your needs.
Source V. Hartikainen
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Sharp but soft triangles in light shades of gray.
Source Pixeden
Prismatic Abstract Background Design
Source GDJ
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin