A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Prismatic Hexagonalism Pattern No Background
Source GDJ
Prismatic Abstract Geometric Background 4
Source GDJ
Remixed from a design on Pixabay. 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
A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
Prismatic Polka Dots Mark II No Background
Source GDJ
8 by 8 pixels, and just what the title says.
Source pixilated
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Colour version of the original pattern.
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc