This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
From an image on opengameart.org shared by rubberduck.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
The original enhanced with one of Inkscapes's filters.
Source Firkin
A classic dark tile for a bit of vintage darkness.
Source Listvetra
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
High detail stone wall with minor cracks and specks.
Source Projecteightyfive