3D Ball using only Charcoal and Cotton

Materials used:
A4 sheet paper
Compressed Charcoal Powder
Cotton
Soft fan brush for shading

Procedure:
Take A4 sheet paper, fold it in half.
Make a circle using any round shaped material on the first half of paper.
Cut the round portion of paper made in first half.
Now secure the three edges using a cello tape or using hand.
Dip a cotton in the Charcoal Powder and start shading with cotton on the round shaped other half of paper.
Assuming light coming from the top left corner, we will shade only in the way which I have shown in the video.
After shading remove the secured edges and open the fold.
Now take the fan brush and do the shading of the shadow as shown in video.