Have you ever wished for cheaper terrain to use in your games? Needed a specific type of structure? Wanted a unique, decorative model? Wondered whether you could do it yourself? Look no further.

Plentiful, and often free, cardboard - especially corrugated cardboard - is a wonderful material for making terrain models. You can find it in most kinds of packaging, in several different thicknesses, for the low, wonderful price of free.

In this Instructable, I will be showing you how I use cardboard to build solid, sturdy structures, layer by layer. The end result can be used as terrain for RPGs and Wargaming, or, quite simply, as a standalone decorative object.

Have fun!

Supplies

Ruler
Pencil
Craft Knife / Box Cutter
Brush
Glue
Mixing Container (Optional)
Water (Optional)
Paper (Optional)

Rendering (Optional):

Plaster / Wood Filler (recipe below)
Scraper / Spatula / Trowel

Painting (Optional):

Paint
Brushes

Step 1: Idea

Every great project begins with an idea! You can get your ideas anywhere, and you can make whatever your imagination dictates. On the other hand, this method is best for large, solid, man-made structures. For this project, I chose to make an arch bridge with triangular piers. For a previous project, I made a section of an earth rampart.

It's always a good idea to do some basic research about what you'll be trying to model. In my case, I researched about different types of bridges, their components, and looked up some reference images. If you want to model an existing structure, look for images and measurements.

Step 2: Sketching

Take a blank sheet of paper, your pencil, and doodle away! While optional, this step allows you flesh out your original idea without constraining your creative muscles with the need for precision. Outline the shapes, draft an overview, sketch some details, and have fun!

Step 3: Blueprints

Take your sketches, your ruler, and draw the blueprints for your project, complete with measurements. This is where you'll want to decide on the scale of your project, especially if you want to use it for games where distances might be important.

In my case, I wanted to use this model for roleplaying games. A quick search revealed that most RPG miniatures range between 25 and 28 mm in height. Considering a humanoid with a height of 1.80 m, or 1 800 mm (isn't the metric system wonderful?), that's a 25:1800 scale; dividing both sides by 25, we have a final scale of 1:72. Now, we can take any "real-life" measurement and divide it by 72 to determine its equivalent on the model. Perfect!

Make sure to always use the same units. If you divide by 72 a length in meters, you'll get its scale equivalent in meters as well!

If you are trying to model an existing building or piece of terrain, you'll have to make sure that the original and scale measurements match as much as possible. If, on the other hand, you're making it up from scratch, then you can fudge things a little as you go (I certainly did that!).

The only constraint I set for this project was that the deck of the bridge (excluding the wall) had to be 3 meters wide, or approximately 10 ft, which corresponds to two squares in several games, notably D&D.

Step 4: Measure, Outline, Cut

Take your cardboard and lay it down on a big, flat working surface. Don't forget to protect your working surface (and your blade) with a cutting mat, or at least some scrap cardboard. Take your ruler and your pencil, trace the measurements from the blueprint, and cut.

Remember: measure twice, cut once. You've probably heard this before, and for good reason. When I don't follow that advice, it shows!

The first layer is down! This rectangle you see is the deck of the bridge, laid face-down.

Step 5: Glue

Take the glue, brush it on your model, and press the surface of the layers together. I use PVA glue, lightly diluted, and it works wonderfully.

Step 6: Make Mistakes

Most likely, you will make mistakes. As you can see by the pictures, so do I! I was supposed to cut where the top line shows, but I botched the measurements and ended up with a diagonal cut.

Fortunately, cardboard is cheap (or free!), plentiful, and easy to work with. Don't be afraid to discard a bad layer and make a new one! If you'll be covering your model with plaster or wood filler, you can be more lenient in this regard, since all but the most glaring issues will be covered up.

Another, more significant mistake, I only noticed after finishing the deck: I had made it a full centimeter too narrow! I had to make a decision: adjust the whole model to fit, or discard the deck and begin anew. I chose the latter. Lesson learned!

Step 7: Repeat

Take your time, put on some relaxing music, and enjoy the way your creation rises steadily from the ground up!

In these pictures, you can see the layers slowly adding up, coming together as deck, arches, and pier, gradually taking the shape of a bridge.

Step 8: Render (Optional)

Take your plaster, wood filler, or similar material, and spread it carefully over the surface of your model. If necessary, work in layers, in order to speed up the drying process and avoid shrinking.

Simple Wood Filler Recipe: If you have no plaster or wood filler, you can make your own with sawdust and PVA glue! Pour some glue onto a mixing surface, and add in the sawdust, until you have a thick, uniform paste. Not only does it work great, it helps bind the model together, and leaves a nice rough finish.

Step 9: Paint (Optional)

There's not much to say here, except to make sure that the rendering material is dry enough. If you want to paint directly over the cardboard, I've read that it can be sealed with PVA glue. Have fun!

Step 10: Finish!

Congratulations! You finished your project, and you should be proud of yourself. Take a break, celebrate, and put your model to good use!

Step 11: Looking Back

What went wrong? What would I do differently?
There were, of course, some issues.
First, the pier alignment was off. I wasn't careful enough to keep the layers properly centered, and so there was some skewing.
The pictures may not show it clearly, but there were also some issues with the curvature of the arches, even though - as far as I could tell - the measurements were correct.
I could also have worked a little slower. I might even have caught my glaring mistake a little earlier!