The Cedar Valley backdrop has been painted with the use of cloud stencils and white flat undercoat from cheap spraycans. The ideas were adopted from a NMRA clinic I attended in the US many years ago, put on by John Lowrance and Miles Hale. There is a video tape available of their technique and it was featured in Railroad Model Craftsman for March 1986.

Although a cloudless sky might look like and mean a great day in the real world it looks artificial in most model railroad settings. The clouds are missed and although this method will not win any art prizes it results in a backdrop that does not focus attention on it but provides an average looking sky. So let’s get on with it:

Backdrop:
As I wanted to curve the backdrop at the corners of the room and to avoid any vertical joints, I used flat 1m wide fibreglass sheeting which was available then by the metre. However, it was expensive ($11 per square metre in 1992) and I believe it is no longer available. I understand however that 26 gauge flat galvanised steel may be available at some hardware outlets by the metre and it may well be as suitable.

Otherwise 2mm MDF can be used but the vertical joins can be a problem. Some have gone to the expense of using Gyprock, which can be seamlessly joined, but it cannot easily be curved at the corners. Hardboard or ply is also suitable but stiffness at the corners can be a problem and vertical joints almost impossible to disguise over time.

When putting up a lengthy backdrop it is essential to get the top level or disaster will overtake you before you reach the other end. First place a prominent mark on the wall 1800mm from the floor, then using a length of small diameter flexible plastic tubing long enough to reach any part of the room from the starting point, wrap electrical tape around the tubing about 300mm from each end to provide sighting marks. Sink it in a tub of water to fill it up and then, with the aid of a helper holding one tape mark against the original, make a number of additional marks at the same level on the wall about every 1500mm or so.

After fixing a line of 50mm x 25mm pine battens around the room level with these marks the fibreglass sheeting was then fixed to the wall in line with the marks every 150mm or so with galvanised 15mm flat headed nails. Note that although I also fixed a line of battens at the bottom this is really matter of choice.

Painting:
If you want to be able to see your painted clouds, particularly in photographs, it is essential that you use a strong mid-blue colour. DO NOT use a light blue! Or one with any green in it! If you have a look at the sky on a bright, cloudless day you will be surprised just how blue the sky is, particularly the higher up you look. Have a look in Australian Geographic or tourist posters and you will see what I mean. You will find that applying the white spray paint will tone down the blue to a level that looks very realistic.

Stencils:
My cloud stencils were made by New London Industries and were purchased in the US. I believe they are still listed in the Walther’s catalog. However, you can easily make your own from a manila file folder or any reasonably stiff cardboard of a suitable size. Simply take a few slides of suitable clouds, project them onto the card and cut out the outline with scissors or a sharp hobby knife. Make sure the resulting hole is a reasonable distance from the edge of the card, as you don’t want any straight lines being transferred to your backdrop.

When you start spraying you will find that it is best to hold the stencil by the top and that therefore you will use only the top section of the stencil. I found it useful to cut the stencil horizontally into 2 pieces, which then gave me 2 choices. Of course, you can make as many stencils as you like.

Clouds:
Take time to study real clouds. They are usually much sharper and whiter at the top (lit by the sun) and thinner, softer, darker or even gray at the bottoms. The higher clouds are usually more formed and those approaching the horizon layered, giving a flat bottom effect. The sky itself is bluer directly overhead and paler as it approaches the horizon and over-spraying the lower areas with white will replicate this effect.

Spraying:
I found the enamel-based spray cans of white undercoat the most easily controlled but be careful, wear a mask, ventilate the room with a fan or two and cover up any areas you don’t want misted in white. An airbrush could be used but it would be more awkward and refilling the reservoir could be a nuisance. Also, white water-based spray undercoat could be used but I have had trouble with spattering and the length of time it takes to dry.

If you can, buy a spraycan handle for better control and to save wearing a hole in your finger. Practice first on some scrap MDF or cardboard to become comfortable with the technique although, if you don’t like the results when you get serious, you can always repaint the blue and start again.

Hold the stencil by its top against and near the top of your backdrop. Spray the tops of the clouds in small, controlled bursts. Take it easy! It’s better to add paint than to over-do it. Watch you do not go over the edge of the stencil, there are no straight clouds in the sky! Make the tops opaque, as that is where the sun reflects most.

The enamel paint dries quickly so you don’t have to wait long before adding body and detail, still holding the stencil close to the backdrop, by layering small sections of the stencils, rotating them as needed to represent the sides of the clouds.

Hold the stencil upside down and spray the bottoms by holding the stencil out from the backdrop about 25mm or so for a softer, less defined edge. Do not make the white too dense here as you will want to represent the darker underneath of the clouds by allowing a little more blue to show through. Some have used gray flat spraypaint here but it can be difficult to get it right.

Leave a border between the higher, more formed clouds and the lower, layered clouds. Start the layered clouds about 300mm above your previously pencilled-in horizon line and overlay the two or three other lines of clouds descending to the horizon. Stand back, and using short, sharp and controlled bursts, fill in any areas that don’t look good to your eyes without the stencil.

Finally, you might also want to waft a fine mist of white towards the lower sections to represent the dust, pollution, etc. that is in the atmosphere. However, go carefully although you can always go back and start again!

Finally:
This does not replace hand painted backdrops. However, it is quick, easy, takes little skill and gives an acceptable result. It is easy to paint over and start again if you don’t like the result. It directs the eye towards the layout rather than to the untidy scenes we often see beyond the layout. Try it, I’m sure you will be pleased with the results.
 
 

John Saxon MMR HLM