Transparency

I want to say a little more about transparency.  Transparency versus Mud.  When you mix too many colors together, or when you mix colors that are not of the same 'temperature' (cool or warm), you get Mud.  It isn't a particular color and it isn't a particular thickness of paint.  But you know it when you see it.  The pigment just sits there dead as can be in a blob on your paper.  No depth, no brilliance, no light, no life.  If you are painting an object that isn't living, you may not mind this effect.  But to a botanical artist, this is a Bad Situation. 

What you want is Transparency.  A few thin washes of compatible colors, and voila!  It is like spontaneous generation right there on your paper.  The thing you are painting comes to life before your very eyes.  What happens is those thin transparent layers just lay on top of the paper, and mingle a little with the paper's 'tooth' (surface texture).  Light can still pass through the pigment.  To me it looks like the subtle texture of the paper actually becomes part of the painting, like the surface of a leaf.  It is almost creepy to see a lifelike leaf start to emerge from the paper.  I think of Michelangelo, who said his role as a sculptor is to release the sculpture from the block of stone it's trapped in.  So I'm uncovering a beautiful oak branch, trapped inside the white paper!  This is what happens to my mind as I sit for hours staring at my painting....