Hi Dennis;
    Do a search on the forum on "doping the dope" by my son Sean. It's basically adding a bit of white dope to your clear as you do your build up while finishing the model. Follow the normal process, and when you get to the pint you are ready to spray color, you already have a white airplane. A local guy came up with this idea and it gives good results. Sean's T-6 that he built from Don Hutchinson's plans is finished this way and Sean gives some details with photos. You can contact him for more specific pics and details. I think he only a slight toot of white spray to even everything out on the top of the model where there was an over lay of red.
   Good luck and have fun,
    Dan McEntee

Thanks for the Tip Dan. Who would have thought that there was such a simple solution?

Where does one purchase White Toner?

    I think he's referring to pigment. Most auto paint suppliers will sell raw pigment, and just add that to clear dope. I painted a couple of free flight models once by using the pigment from Floquill railroad paints that had separated and settled to the bottom of the jar and added that to clear nitrate dope. I first read about this method in the old plans book for free flight scale WW-2 rubber powered models that Model Builder put out years ago.
    One thing to remember when painting a stunt model, especially white, is that you will be covering some of the base coat up with trim colors, markings and other details. Getting even coverage is more important than trying to make your model look like your refrigerator! Adding all the other stuff will make it all blend in.
  Type at you later,
   Dan McEntee

I think "doping the dope" is a great idea. 

Doesn't just have to be white?

Has anyone added yellow tint to dope for a model who's primary color is going to be yellow?

I might just give this a try.

The best base coat under yellow is white.  Anything else will make the yellow look muddy.