A toilet paper roll that is square… no, round… no, squaround!

He was awarded a prize for optical illusion of 2016 and anyone can replicate it using the so-called “core” of toilet paper rolls.


The Italian version of Wikipedia cites many names for the semi-rigid central part of the toilet roll: among them, mini-roll, tube, mini-tube, or, as we say in tissue jargon: the “core”.


It is what’s left after the paper is finished and it often finds many reuses, some on the brink of the absurd. It’s a mystery why this small object that – once its function as support is terminated – is rather useless, has always unleashed a desire to play in young and old alike, who enjoy vying with  recreational-creative uses and revisitations.


Kokichi Sugihara, a soft-spoken Japanese math teacher, has always dabbled with optical illusions, but last year, he outdid himself by creating an extraordinary one entitled “Ambiguous Cylinder Illusion: Rectangles and Circles”. To do this, he used small cylinders exactly the same as the cores of toilet rolls (with which anyone can repeat the experiment at home).


Finalist in the Illusion Of The Year 2016 award, Sugihara’s invention is truly astounding because by exploiting the image reflected in the mirror, he makes a round shape appear square and a square shape round. The illusion works only and exclusively if the spectator is at a particular angle with respect to the setting.


After seeing how the “ambiguous cylinders” work, anyone who wishes to replicate the illusion can do so by taking a core, pressing it to make it “square”, tracing a wave that touches the folds and positioning the object in front of a mirror until you find the proper angle. You can also find a simple tutorial on line.