Found this thread via a google search for underpainting; what a total bunch of info, mazin!
I'm not a concept artist, just a painter, but was never trained in any way (even though I did an illustration degree, they kinda skipped all of the important stuff and left us to our own devices before basically say 'no, that won't do', or 'well done, that's better'.)
Anyway, glad to be here and now for my question: I paint in acrylic, am having trouble with my paintings having any sort of life when they are finished. I've been experimenting with grey and also complimentary underpaintings, glazing over the top, but the colours are looking dull. Is it imperative that I add some sort of medium to my paint other than water- will it make a massive difference, or should I just continue to experiment until I crack it?
Or should I take the plunge and use oil? (please say no, I cannot imagine the drying time, the cleaning process, the fumes, and not least of all the seemingly endless opportunities to mess with the paint while it is still drying!)
Any response from an acrylic aficionado will be much appreciated.
The old masters did not use Grisaille.If Tintoretto or El Greco at times used a white under painting for some areas some of the time there is an element of Grisaille about them but Poussin,Rembrandt and Titian just plain did not use Grisaille.Think of Grisaille as a technique to train with if you are studying the old masters.If you use it as your main technique through out life that is your choise but you are in no way aspiring to the old masters.You may however be painting very excellent paintings so more power to your elbow if it works for you,you've just got nothing to do with Rembrandt or Titian thats all.
I suppose the best book on Rembrandt is Ernst Van De Wetering :The Painter at Work which gives a serious but understandable analysis of his technique this explains that the artist blocked in a loose/rough intention of his composition. (which was actually not monochrome to be tinted with colour like grisaille)This would be given multiple layers in varying textures from glazes to impasto etc in a way that is not suited to painting over a grisaille.Often(though not allways)a central aspect of Rembrandts ability to render flesh was "The Turgid Medium effect" which obviously is inconsistent with Grisaille.So generally speaking if like Titian you are using multiple layers its not overly effective as a strategy to start with a monochrome under painting especially if your working at a time of limited access to many pigments and have to create a broader range of colours not only by mixing on the pallete/pots but by glazing one colour over another for optical mixing.But I suppose the most obvious reason Titian or Rembrandt did not work this way is because the whole point or their style was one of improvisation of composition and/or pose, as they painted they revised in order to remain spontaneous.
By the way Im on your side,as my post above points out Grisaille is good not bad -but let me prove my opinion on this,there was a guy went to my collage a couple or years after me who has done good stuff with this technique -Google him "Paul Reid" scottish painter-I hope Ive not sounded "Up my own arse" as we say around Glasgow but we will have to agree to disagree on the matter of the old masters using grisaille in the way it is understood today.
I always use burnt umber for underpainting, even in digital medium. Having worked in traditional oils for a number of years, can't imagine starting the illustration any other way. Here are some of my underpaintings with a few words about the process.