Grooved/Corrugated Brick

The origin of these bricks is still unknown. As far as I know all known bricks come from the same German collector.

Logo: modern logo
Inner wall: thick
Inner ribs: None
Inner tubes:
Flowrib / center line inside top surface: No.
Mold pip: on the stud.
Mold number: None.
Mold position numbers: None.
Intellectual property protection: None.
Design ID (3001): No.

Remarkable features:

  • Grooves/ridges on the inside top surface.
  • No mold markings

Colors known: Transparent light blue, transparent neon-green.


  • Where were these bricks made, and what were they used for?
  • Why were these ridges made?
  • Can we find more colors?

The brick does not work as a reflector.

Very recognisable ridges inside the top surface. No other markings inside the brick.

Showing the profile of the corrugated grooves/ridges inside the brick.

[Original posts and comments on Flickr: 1, 2, 3.]

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