I love the bold use of black ink, it really captures the dark emotions you associate with Batman. And I have to say, I would never have thought to use salt as an art medium. Clever! It adds grainy texture which brings the piece to life, makes it seem 3D. Brilliant piece!
It's great you don't trace. You definitely learn more when you have to freehand rather than trying to be a copy-machine. And although the picture itself isn't exactly intricate, your drawing is proportionate and wonderful!