I have an addiction to using reflections
It is a very well written tutorial, easy to read, hard to do (for me anyway) but on step #2 - "filled circle starting at 0,0 to 499,499" I did not understand that part, so I made a circle and then stretched it to a size of 499x499 (I don't know where 0,0 is on a canvas) Also on step#10 "metalise", when I tried this stage it turned the disc black (Curves made it worse) I will try it again following the updated method and see if I can get it right