First,I make a few thumbnails for composition and one larger sketch that the
owners can look at before I sketch it onto the wall. I sketch with a white
chalk pencil which makes it easy to paint over and also wipe off any lines
If it is a large area, I will usually base coat the wall first with the
background colors. For instance, if it is to be a rainforest, I will base in
the blue of the sky and the middle green of the trees and some of the ground.
This will be done in large flat bands because it would be too hard to paint
around objects. In essence, I handle it much like an oil painting from
background to foreground.
I leave out all detail in the sketch. I mainly put in contours for placement.
Details are the last step in the painting. To do shading with acrylic, you can
get an extender in the art stores or supply catalog. It will give you more
work time to blend. I also blend by double loading the brush with 2 colors and
stroking once or twice on waxed paper to blend them together on the brush.
For paint, I have used commercial liquid acrylics and if areas are
exceptionally large, I have custom colors of latex wall paint mixed in pints
or gallons. These are mainly the purest primaries I can get plus a black and
a white so I can color mix what ever colors I need. Large areas are custom
mixed ...I don't mix these (like sky, background greens, etc).
I usually get eggshell finish so it can be washable. I find these are quite
permanent and it is easy to correct mistakes. Just paint over them! If you
need a durable finis, you can spray or coat with polyurethane but be aware
that it will be hard to paint over again.
Hope this helps. :)