I think I like the idea of skyboards-- or, more accurately, view blockers. My feeling is that they should block the line-of-sight from one side of the table to the other. This will force the viewer to walk around the layout to follow a train, making the layout seem larger.
Although some modules have attached skyboards, a number of modules (including most of my own) do not. So I think a system of 'portable' skyboards is useful.
I made a noble attempt with foam insulation glued to a plywood core with angle bracket legs, but I was not happy with the design-- the legs were permanently attached, and were awkward to transport.
After thinking about it for a while, I came up with a simple, portable, variable design.
Quarter inch plywood panels are inserted into slots in 2x4 lumber feet. With a 'sky' panel in a central slot, I can add 'mountains' on both sides of the sky: I envision one or two layers of mountains made with 'mountain paint,' and a frontmost layer using a photographic backdrop. Or, I can stack 2 or 3 layers of 'city' backdrops to create an urban area.
The advantage of this method is that it's easy to slip the panels out of the feet, stack the skyboards into a compact bundle, and haul the bundle to or from a show. No angle brackets to jab the inside of my truck!
First, the feet. Start with 10'' long chunks of 2''x4'' lumber. I started with 12'' long chunks; this turns out to be at least 2'' too long. You'll need at least 2; I made about 6 to start with.
Slots are sawn into the narrow edge of the 2x4s. I marked the center lines for 7 slots, centered along the length of the lumber. The slots are 1'' apart and 1'' deep. I marked the sides of the 2x4s with a 1'' 'depth mark', then used a power miter saw to make the slots. I carefully guided the saw into the 2x4s until it just touched the depth marks. I used multiple passes of the saw to make the slots wide enough to hold 1/4'' plywood skyboards, and a little extra room. Since this is a portable installation, the slots are wide enough to allow the panels to slip in and out without a struggle.
The skyboards are simply pieces of 1/4'' (or 3/16'') plywood. The photos below show how the sky- and mountain-boards are used. The first shows two 'legs,' a sky panel, and 2 mountain panels. The next 3 show sky, 3 mountains, and 2 legs assembled behind a module.
As you can see by the back view, there are 3 remaining slots for mountains on the other side of the layout.
The first skyboard is 18'' x 48''. This is for the 'sky.' I gave the top an 'artistic' curve, and painted it blue on both sides and all edges. Since it's plywood, it'll take a few coats of paint to obscure the wood grain.
The remaining panels are for the backdrops of your choice! I made several panels of 'mountains.' They are shorter than the sky, and overlap each other in various ways.
Because a TTrak layout can be assembled in a variety of arrangements, skyboards in varying widths are necessary. I have made a set of "skys" in 2, 3, 4, and 5 foot widths.
This design works well with my "original design" modules-- they're 8-1/4'' deep. This means that on a 30'' table, I have 12-14 inches between the modules (back-to-back). As module depth increases, to 12, 13, maybe 14-3/8 inches deep, the available space for module feet shrinks! I have a couple of ideas that may help, but they're less than half-baked at this point!
Since modules are getting deeper and deeper, the available back to back space between opposite sides of the table is shrinking rather frighteningly!
Even if there's enough space for the sky and hills, you still need a little space for long legs to hold them up!
Here's an idea for a low-profile ViewBlocker Holder.
It's a series of wooden or plastic blocks fastened to a reasonably sturdy strip of metal. The metal strip can slip under a deep module and provide enough leverage to keep the sky upright.
If you only have room for 2 or 3 items you can make a set of legs with just enough slots for these items, and the legs will still slip under the modules.
At my local Build-A-Home center I discovered folded insulating board. It's 4' x 50' x 1/4'' thick, fan-folded (zig-zag folded) every 2 feet. It's a nice, even blue on one side, with black 'advertising' on the reverse.
I made a 3 foot wide skyboard by slicing off an "A" fold of zig-zag board (making sure the outside of the fold was the "blue" side and not the printed side). I cut it 18'' tall (measuring from the fold), and 3 foot wide. It slips into two of the slots in the 2x4 feet.
I expect to make more panels with cityscapes. The sky's the limit!
There are times when a sign would make it easier to know you're looking at a T-Trak layout. Extend the center 'sky' board an additional 6'' higher and use the extra space for your identification:
Here are the cutting diagrams I used to build a whole mess of Sky Boards and Mountain Ranges. These are all 4' x 8' sheets of 1/4'' plywood.
The first two are the ones I cut in the Summer of 2006. This gave me 2 each five, three, and two foot chunks of sky, and 2 each five, four, three, and two foot mountain ranges, and 1 four foot sky. Since I already had 1 four foot sky, this gave me two of each.
Note that the 'rolling hill' panels show how I envision the hills overlapping. These are not cutting lines, but guides for how I plan to paint the hillsides.
When I started using these, I discovered that if I wanted 2 mountain ranges on each side of the sky (for a two-tiered effect) I really only had enough mountains for 1 side of the sky! So, in the near future, the 3rd diagram will provide me with 2 more of five, four, three, and two foot mountain ranges, although one of the 4 foot mountains will be a couple of inches shorter than the one cut from the original cutting diagrams.
While working on my skies and mountains I needed a way to hold them while the paint dried. I built a pair of L-o-n-n-n-g skyboard feet with a couple dozen slots. Here are my mountain boards lined up for paint or other work.
Here's a possibility for sky at the corners of a layout. Once again, I haven't built one of these!
Material is a "Quicktube" or other concrete-form tube from your local home center. These come in nominal diameters of 6", 8", 10", and 12". At each size Quicktube comes in 3 diameters-- one exactly at the nominal size, one 1/2" larger, and one 1/2" smaller. The manufacturer does this so it can nest multiple tubes in the space of one for shipping.
You'll need at least 5 different diameters, ideally spaced 1" apart to slip into the slots in the legs. Fortunately, the 'nominal sizing' of the tubes makes this possible-- using the 'minus' and 'plus' sizes, you can select tubes from 5-1/2 to 12-1/2 inches in diameter, spaced every inch! You may have to search several stores in the area, because the tubes are only inventoried by the nominal sizes. Bring a tape measure in case there're only one or two tubes in a given size!
Starting at 12-1/2, for 5 diameters you can get 12-1/2, 11-1/2, 10-1/2, 9-1/2, and 8-1/2 inches.
You only need at most 18" of tube per corner, so the nominal 4' tubes will give you enough for at least 8 corners, with enough left over for extra mountains or cityscapes.
Each corner needs only a 90 degree arc from each tube. You'll need to mark 4 cutting lines equally spaced along each tube. These tubes are easy to cut with a hand saw; pick something with fine teeth so the edges of the cuts don't get all fuzzy!
Use the middle-sized curves for the sky; the rest are mountains or city. Round the edges of the arcs to match your normal sky. Paint, and use.
Once you've got your sky and mountains cut out, paint is the order of the day. I recommend a first coat of BINZ or KILZ to seal the plywood before you roll on the color. B & K are pigmented shellac and are intended to seal smoke damage and water stains so you can repaint easily. In our case, latex paint has a tendency to raise the grain on plywood. B & K will minimize this and leave a nice, white background.
The sky gets a coat of blue on both sides. I bought a couple of gallons of "blue" from the 'oops' shelf at my local home center. It'll last a LONG time! You may need a 2nd coat of blue for evenness; be sure to dab paint onto the edges and into any gaps in the plies.
Mountains take more work! If you look at the cutting diagrams, the 'mountain' pieces have extra lines showing where I imagined different strata would cast shadows on the outcroppings farther back. If you look at the pictures above showing the sky and mountains in use, the black smudges are the (over-enthusiastic) shadow lines.
I used 2 shades of green and some black to paint the mountains. I rolled on the lighter green, then used a sponge and daubed on the darker green, leaving blotches of the lighter green poking through. The black was used originally to make the shadow lines, but then I mixed a batch of -really- dark green to make a more subtle shadow.
I imagined the shadows were cast by the Sun shining from the left end of the mountains. When I turned the mountains over to paint the backsides, the Sun stayed put-- the shadows were still cast by the Sun shining from the left. The means when I layer two or more 'mountains' all of the shadows will be facing the right direction, no matter which side of the mountain is showing.
If you look at a range of hills marching into the distance, the hills nearest you are the greenest and clearest. Each successive range is a lighter shade of green, due to atmospheric haze blocking part of the light. I wanted the same effect, so I needed to add 'haze' to some of the mountains. I decided to make one side of each mountain 'hazy.'
I used a paint product known as "Faux Technique Glaze - Tinting Base." It's basically latex paint without pigment. Used by itself, it would dry perfectly clear. I added just a dab of white latex paint to the glaze-- probably just a teaspoon in a quart of glaze. It rolls on pasty white, but dries almost clear.
Then I rolled the glaze over one side of each mountain. This lets me pick any pair of mountains and always have a 'hazy' mountain to simulate distance.
Here's an alternate idea I dreamt up before the slotted 2x4 idea hit me. This one is a hinged leg that clamps onto a naked piece of foam insulation to hold it upright. If the gripping part of the clamp is tall enough (taller than the diagram indicates) it shouldn't be a destructive clamp. Plus, you can clamp onto different parts of the foam to spread out the wear.
I never actually built one of these, so builder beware!
I discovered an almost instant method of creating a stand alone view blocker. At my local Build-A-Home center I discovered folded insulating board. It's 4' x 50' x 1/4" thick, fan-folded (zig-zag folded) every 2 feet. It has a thin plastic film on both sides, but this doesn't need to be removed.
The board I found is nicely blue on one side, and covered with black 'advertising' on the back side. To turn this into a view blocker, do the following:
1) Figure out how long you want your view blocker.
2) Unfold enough panels of the folded insulation to have enough length. You have to unfold more than the straight-line distance because the zig-zags take more distance than a straight line.
3) Slice off the necessary length from the bundle. Add one extra panel!
4) Shorten the 4' height down to 18". Do this from both edges; you'll have -2- 18" tall panels.
5) Flip one panel and arrange them so they are back-to-back with the black advertising between the panels. This is where the extra panel will be needed-- you have to shift one panel sideways so the zigs on one panel line up with the zags on the other.
You don't need to glue them together, they'll stay together pretty well. You don't need 'feet,' as long as the zig-zags are wide enough, they'll stand on their own.
My first view blocker was a sandwich of 1/2" blue foam / 1/4" plywood / 1/2" blue foam, with shelf brackets for feet. It was 48" wide and 18" tall.
There were a few problems with this view blocker: (1) it was big. Blocked the view, but hard to transport; (2) it tended to pick up fingerprints; (3) those legs sticking out made it tricky to load into the cab of my truck without poking through the ceiling. I'm including a few photos of this original view blocker, although I'm no longer using it.