This series of classes is perfect for me.  I've heard the terms explained before,  i.e. in YouTube. But this course finally gave me the ah hah moment of really understanding (as much as you can without years of practice). I used an 'economy' brand of acrylic paint and had some interesting results.  I'm not sure if these interesting results were do to the brand of paint or are just the nature of the colors or Acrylics in general. But otherwise I learned a lot... especially about using complementary colors to tiny the shadows.  This technique worked very well, but trying to lighten with titanium white is disappointing.  I look forward to your remaining intro classes........