Hello, I am sorry for the late reply. On that day I did 3 such drawings;) in the museum and corrected 2 of my student. I have been teaching every day a private class this week, which finished yesterday, so somehow I have missed your nice comment. The speed comes from the amount of work one has invested. It is the same as playing a musical instrument. The more you do it, the faster it gets;))). I will check your blog now and follow you.