Draw constructions in shadows with thicker traces, and constructions in light with thinner lines. Test it by yourself: draw a circle, then go about the bottom of it with a heavier line and immediately it gains volume and appears like a ball. Pen and Ink drawing is a straightforward https://simonquvuu.blogscribble.com/37120377/the-greatest-guide-to-how-to-draw-with-ink-pens