Liquin as a medium definitely dries much faster than the "Oil+Dammar+Turp" medium.

To date, I have never seen a successful painting with just "back lighting", however I'm open to the idea and curious to see if it will work for you...

Thick first layer
 

Karin, when you say the FIRST layer, which layer do you mean? Isn't the first layer the underpainting and all layers after this one glazes?

I am trying to understand this whole process of glazing and scumbling. I've taken notes from many posts so I can give this a try.

Thank you,
Joan

More on a thick "first layer"...

Sometimes an artist will do a drawing (or sketch) directly on a canvas (white or imprimatura) with a "wash" (thim paint) to determine design, anatomy, etc. This is NOT the "thick first layer of paint" I am referring to...even though it might actually, technically, be the "first."

When you begin making the monochromatic (grisaille) underpainting this is the really thick buttery first layer that I am talking about.

For those who are not working with an underpainting and are working directly (a la prima) THIS is the thick first layer...and it may be over guide lines or a thin drawing on the canvas...

Note that when your first thick layer of paint is dry, the dark areas (deep shadows) will generally be very thin (glazes or scumbles) on top of that....it will give the illusion that the "canvas" shows through. (If you go to a museum and check out an Old Master painting you can observe this....)

When you paint in the classical way with oil paint, the canvas will (early on) be covered with thick paint. In subsequent layers the paint will be even thicker in areas of light....and thin in the deep shadow areas.

I hope this clarifys and not "muddys up" things further for you...