It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The tile this is based on can be had 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
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
8 by 8 pixels, and just what the title says.
Source pixilated
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
This one needs to be used in small areas; you can see it repeat.
Source Luca
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk