Grille Time!

Print this out and try it out for yourself.  You may want to have a strong light between the grille and the encoded text.

This grille was randomly seeded and is reversible, similar to a chess cipher and a classical grille. 

Visual Decoding

Planned Pixels

Shadow Circuit

Behind a Leaf

Historic Software

Gallery of 49 (Small Bits)

Best Toddler Toy