How to Draw 3D Block with Pen in the Air | Optical Illusion

This is a optical illusion drawing with markers, charcoal, black colored pencil and white colored pencil. I hope you like it and please share and leave your comments. Thank You. If you have questions, we will gladly answer them. Thank you MATERIALS: Pencil 2b Markers Charcoal Prismaclor Premier black and white colored pencil