The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Tile-able Dark Brown Wood Background. Feel free to use it as a background image in your designs or somewhere on the web. By the way, the color seems to be close to Coffee Brown.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Tiny circle waves, almost like the ocean.
Source Sagive
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
The base gradient edited so now more details are rendered.
Source Lazur URH
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
A floral background formed from numerous clones of flower 117.
Source Firkin
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
An alternative colour scheme for the original seamless texture formed from an image on Pixabay.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
No relation to the band, but damn it’s subtle!
Source Thomas Myrman