A "stereogram" is a "optical illusion art" form in which you can see a totally different picture emerge from ordinary patterns when you look at it with intentionally unfocused eyes.
Thanks to with Nango (Co., Ltd.) unique technology, this optical illusion art known until now only on planar printed matter is modeled in a three-dimensional like unevenness to obtain a stereogram on thick metal. When you look at the pattern on the central part with intentionally unfocused eyes you can see letters and symbols emerging.
A Stereogram can be seen only when you look at it with intentionally unfocused eyes which means that compared to everyday life you are using your eyes in a different way. To watch Stereograms is a good exercise for the eyes so it is ideal for people with overused eyes due to PC usage and also for elderly people who lost their eyes muscles elasticity.
The two ways to watch Stereogram are the " parallel method "and the "cross method".
If it is difficult to shift focus there is also a method consisting in drawing 2 points and keeping your eyes unfocused until you see a third one appear.
If you look at Stereograms in a normal way, you will only just see patterns but by shifting the focus of your eyes you will see that the image emerging at a certain point. The surprise and impact leave a strong impression on the people who are watching. So please, enjoy the world of Stereograms.
The Stereogram can not be seen if there is an extreme difference of visual acuity between the eyes because this technique requires both right and left eyes deviation.
In some cases tool marks (edge tool cutting traces) may remain but please consider them as one of Nango-Bori characteristics.