This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Abstract Ellipses Background Grayscale
Source GDJ
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo