Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The base gradient edited so now more details are rendered.
Source Lazur URH
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Prismatic Chevrons Pattern 5 With Background
Source GDJ
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell