About the subtlety of halftones

William Bouguereau courtesy artrenewal.org

My Dearest Stape;

Can you please address the magic behind the half tones? As I grow as an artist, I find little written about the importance of them, and how to use them correctly. I truly need advice here!
Love!............................ Ms. Darlene Lubriderm

Darlene;
That's a big topic. I will throw out a few pointers. The painting above is a great example of beautifully managed halftones. Here are some bullet points on halftones;

• The halftones ARE A PART OF THE LIGHTS!
• Look at the painting above and notice that the halftones (those parts of the light that approach the shadow and explain it's structure) are always way lighter than the shadow. They are lighter than the reflected lights.
• The most common drawing error is to represent them darker than they are, to overstate them. This instantly destroys the illusion of form and gives the drawing a dirty look. If you walk through any art school you will find endless pads of crudely drawn figures from life drawing class bearing exactly this fault. The models look like they are wearing rubber wetsuits.
• This overmodeling happens because the tendency is to compare them to the value of the rest of the lights, that is, they look darker than the lights and in order to make them look darker, the tyro overstates them. If they are compared to the entirety of nature they will appear in the proper value. The "big" look of nature is more valuable in comparison that a piecemeal approach. Nowhere is this more vital in obtaining the proper values for halftones.
• Look at the subtle value changes about the cheek and around the mouth of the painting above, see how subtle those transitions are? They are enough to turn the form, but they don't chop up the large presentation of the lights. They are a small variation in the value of the lights and only that, they are not part of a different light.
• If you squint at the Bouguereau above the halftones almost disappear. Delicacy is the key. Understate your halftones and you will usually find they are about right. Never paint them any value that is found in your shadows. Often the addition of just enough color to make them different from the highest lights will drop their value sufficiently to work.