Simply stated, taking a class that gives you a certificate is mostly for the benefit of your clients.  It tells them that you have completed a course on how to use a specific tool or product correctly.  It can distinguish you as a professional and not a diyer.     I think anyone who has been in the decorative (faux) finishing industry for many years can remember in the early 2000’s when the diy shows came out and gave the people watching the shows a sense of, decorative finishing is easy and anyone can do it.  Sure, to some degree anyone can.  But there is a vast difference between the quality of their work and the quality of a professionals work.   Epoxy is another example.  When I first learned how to use epoxy it must have been around 2007.  I had to take a class before buying any epoxy product.  I’m glad I did.  I can imagine I would have spent more money on product then on a class trying to figure out on my own the proper way to use it.  Nowadays, anyone can buy it and I read a lo