up and down arrow keys to change pen size
pencil i used: https://www.google.com/search?q=pencil%20png%20transparent&tbm=isch&hl=en≷=ar&tbs=ic:trans&sa=X&ved=0CAIQpwVqFwoTCNC_8q2My-8CFQAAAAAdAAAAABAM&biw=1366&bih=665&safe=active&ssui=on#imgrc=EhRQTHxXfJlDlM
