Pencil drawing - Royal format - 3 hours pose

Here are some drawings made during my course at Paris' Fine-Art workshops.
I didn't have an artistic background. I felt necessary to fill my gaps in anatomy and to practice "academic" drawing. It is 3 years now that I compel to practice this hard and formative exercise : living nude models drawing.
Progression is slow, often too slow. However, when I take a look at my old drawings and my present ones, I can notice some improvement. Fewer anatomy mistakes. Composition is often better, stoke is more pleasant, lighter, inquiring.
Poses may be short for roughs (5 to 10 minutes), or long for studies (1 to 3 hours).