Rendering Glass objects with a reductive method in charcoal 

Renzo, don't worry about the quality of this drawing, there's no quality, so there's nothing to worry about. The author of the channel does not understand the meaning of what he is doing at all))) This is called dense amateurism.

Учись у настоящих Мастеров, вот один из них ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-WGVECguw2Ik.html&ab_channel=DrawingArtAcademy