CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A new one called white wall, not by me this time.
Source Yuji Honzawa
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Prismatic Hypnotic Pattern No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
A comeback for you: the popular Escheresque, now in black.
Source Patten
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
Prismatic Hexagonalism Pattern No Background
Source GDJ