, if you had a red area 
you wanted orange, you would first allow the red area to dry -&nbsp; possibly a 
matter of days. Then you would mix your yellow paint with a special glazing 
medium to make it fluid and transparent, and add a thin layer on top of the red. 
The result would be an orange with a different look that you would get if you 
simply mixed the red and yellow.</p>
<p>When working in layers, it is important to honor the fat over lean rule. A 
lean layer has relatively little oil - either