Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Prismatic Abstract Line Art Pattern Background
Source GDJ
Found on the ground in french cafe in kunming, Yunnan, china
Source Rejon
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin