Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin