This version of demo video is made only for members. 
Member only version has the photo reference, run real time (1x) speed and 4k resolution.  
VIDEO QUALITY & SPEED:   - Video quality: 4k   - Video speed: Real time (1x).  
MATERIAL: - Willow charcoal stick. - Knead eraser. - Stumping tool. - Finger. - HB Charcoal pencil. - Arteza drawing pad (premium). * Full list of Charcoal drawing material and more detail are at zinlim.com/qa