thomforsyth:

ARE THE HORIZONTAL LINES PARALLEL? | Cuatro Cutros

The horizontal lines are distorted by the squares, so that they appear crooked. The effect caused by this perception is based on Zöllner illustration published in 1860.

The modular shelving that comes from this illusion consists of shelves with grooves where the metallic structures are fitted. The different position of the clefts in each shelf allows the displacement of the squares to create the effect.
The plate has four possible positions, so it can be accessible from both sides of the shelf.
The shelving can be also used as a room divider. You can choose the height depending on how many rows you stack.