About Trompe L'Oeil:
Trompe l'oeil murals are paintings, usually on a wall, (or ceiling, floor etc.), that when viewed from the right position, should deceive the viewer into thinking it is real.
Trompe l'oeil is French for " trick the eye ".

The main concern in these paintings is to create an illusion of a three dimensional space. Generally these are commissioned and are especially designed for a particular situation and are not moveable, but they can also be painted on stretched canvas or panel and hung the same way as a conventional painting.
The main benefits of trompe l'oeil murals are that they can create an illusion of a space that could not normally exist, would not be affordable to create or would defy the laws of nature.

Medium and materials:
All the murals were painted in signwriters acrylic, except for the "Tilly Corporation Foyer", "English Window" and "Studio Window", which were painted in artist's oils.
I use an airbrush to blend colours together where necessary which is powered by a small (silent) compressor which has around the same noise level as a refrigerator.

Perspective:
The perspective in most of the murals has been calculated to look right from a single viewpoint and is one of the most important elements.
From this viewpoint the trompe should blend seamlessly with the existing architecture and all the objects in the mural should look like they would if they were there in real life.
If one were to move closer to the mural, the image would look more like it was seen through a zoom lens, and if further away, like a wide angle lens.
In any case, if the viewer is not near the optimal viewpoint, the mural will look more like a painting rather than a trompe l'oeil.
Restricting the viewing position can be achieved in several ways.
One way is to have the mural initially seen as the viewer enters an area, possibly through a door. In this case the trompe creates an initial impact.
Another way is to have the viewing position in an area where people will most likely frequent. A lounge or dining area would be appropriate.

Procedure:
After discussing concepts with a client using rough sketches to solidify any ideas, I will produce a technical drawing similar to the one on the right. This stage will determine what is and isn't possible and the end result will be an accurate scaled version of the mural.
(This one is sketched in pencil but in most cases I am now able to design on computer, allowing me to modify the design more easily. Please see software for more details.)
If the design is acceptable, the image is re-drawn full size onto the wall or panel and painted.

Directly on a wall:
Trompe l'oeil murals are generally most effective when painted directly on to a wall. There are few limitations when designing the mural, because there are no constraining boundaries, except of course, the limits of the wall.
Objects could protrude from the wall and cast a shadow on the surrounding wall, or an opening in the wall could be irregular, such as a hole in a plastered brick wall.

The surface of the wall has to be reasonably smooth, and in good condition.
If the paint underneath the mural fails somehow, or the wall cracks, so will the mural.

Panels:
An alternative is to paint the mural on panels and fix it to the wall.
I generally use MDF, (medium density fibre board), for interior murals which is basically reconstituted wood pulp, pressed and glued into a variety of thickness and sizes.
It does not have the same tendency to warp as plywood does, and has a smooth surface. I have also heard it referred to as 'craft wood'.
External murals can be painted on cement sheeting or Weathertex, a masonite like product that is produced for external cladding.

Size of the panels is limited by manufacture and transport, therefore for larger murals, multiple panels need to be used and thought has to be given to disguising the joins.
Also, If using panels, the mural has to be contained within a border and the edges of the mural needs to represent the edges of an architrave, or similar architectural feature that protrudes from a wall. (E.g.. an architrave around a door or window.)

Having said this, there are advantages to painting on panels as opposed to directly on to a wall..

It is more economical to paint on panels, because they can be painted in the studio, rather than traveling to the site. (A huge advantage for remote locations.)
They can also be relocated after installation, however because trompe's are designed to blend in with the surrounding architecture, moving them may take them out of context.

Because I control the priming of a panel, the integrity of the paint film may be better than if painted on a wall.