Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A white version of the very popular linen pattern.
Source Ant Ekşiler
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Prismatic Polka Dots 3 No Background
Source GDJ
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
Abstract Tiled Background Extended 6
Source GDJ
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin