Making a Desert Terrain Mat

We recently ran our annual demonstration game at the Pine Rivers Model Train & Hobby Expo. The show is put on by the Members of the The Railway Modellers’ Club of Queensland Inc.

This year we were doing a Biblical era game using Field of Glory rules with 2000point armies.The armies were Hittite & Sea people Vs New Kingdom Egyptian all in 1/72 scale. As I wasn't supplying any figures for the show I offered to make up the terrain. In this case it would be a desert theme and I was keen to do a gaming mat as I'd need this anyway for wargaming the Sudan and WWII North Africa, so it certainly wouldn't go to waste. I thought I'd document the process I went through just in case others may be interested in trying this out, if not to the same scale as I did. The mat size I produced was 4.5m x 2.4m (14 3/4ft x 7 3/4ft). I did a bit of experimenting prior to starting the main project to check out different materials (sawdust, kitty litter alone) and paint colours to try and get it close before heading into the full scale project. What is listed below is the outcome of those trials.

Materials:

• Calico Material - I had seen suggestions of using Canvas but Calico was cheaper, lighter and essentially would provide greater flexibility in being able to be shaped to the terrain required while still providing the necessary strength for such a mat.
• Sand - I had two sources for this. Beach sand (from the beach), only a small container, and I purchased a 20kg bag of coarse sand from the local hardware. I then sifted the sand into 3 different sizes, Large, Medium and Small. The Large being similar in size the the Kitty Litter. I only used the Medium and Small. The idea I had was that the Kitty Litter would be lighter and therefore I'd use it in place of the Large sand. I'm not sure it made that much difference in the end.
• Kitty Litter - Cheap supermarket brand, used for the large rock effect.
• Caulking and caulking gun. I chose the cheapest I could find at the hardware store in the colour brown. Brown because if any of the large sand or litter can loose the dark brown colour would just look like a small hole in the ground. I did try a lighter colour in the trials but it didn't look as effective. This is the acrylic based filler that is used to fill the gaps in tile work and has to be paintable. It isn't silicone based. It's sometimes referred to mastic in other areas of the world.
• Scraper - For spreading out the caulking.
• PVA Glue - I mixed this in with the initial paint coat only and adding the grass tuffs on the final product.
• Sample Paint Pots - Used Earthy tones. Darker to lighter as in the photo below. I actually bought two pots of the darker colour as it would be the most liberally applied. Each of these is approx 500ml. I used about 700ml of the darker colour mixed with PVA. The second about 400ml and less than half for the other two colours.
• Paint Brushes. The larger one I used on the first two coats. The smaller one with the last two dry brush coats. This was a very cheap brush.
• Rag - For patting down the sand into the caulking (see explanation later)
• Grass Tuffs - I made these myself but any commercial ones will do - will just cost you a bit depending on the size of the matt and how many you want to use.
• Other items I ended up using was some thumb tacks and 20mm PVC piping to attach the mat to so it could be rolled up.

Materials used in the making of the Gaming Mat

Process:
(Note: some of the photos may not be in strict order in respects to timing but may be placed to best represent the step in the process being discussed.) 

• Applying the Caulking: Because I was making such a large mat I thought it would be important to ensure the material underneath didn't move too much while I applied the caulking. I had some particleboards that I use as my gaming tops and I thumb tacked the calico material to these boards as best I could to stop it moving around. Then using the spreader I spread the caulking evenly over the material

Applying the Caulking

Spreading the Caulking

• Adding the Sand and Kitty Litter: At this point I applied the sand. Because the caulking isn't a real wet type of substance it was necessary to use a rag to pat the sand down into the caulking. I spread the large kitty litter first then each finer sand coarse finishing with the beach sand. The beach sand doesn't offer a lot of grain itself but puts enough of a barrier over the caulking so that it didn't stick to the rag as I was patting the sand down. Now there is probably a few questions that come to mind. 
• Would it have been easier to just coat the whole material in paint without the caulking and then add the sand or maybe add the sand to the paint and either avoid the caulking altogether or just do the caulking in one hit and do the sand and paint after it dried? My reasoning for doing the approach I did was that I wanted a little more control over the sand application. I wanted to clump larger bits together and sort of give the effect that there would tend to be piles of larger stuff together rather than everything just being scattered evenly across the whole terrain. Trying to spread sand over large painted areas didn't appeal and I felt adding the sand to the paint beforehand would make the application too uniform. The caulk on the material is also important as it adds to the mats strength and painting alone would have likely been messy as I'm sure the paint would have seeped through the other side.
• Isn't it possible to just texture the caulking without needing the sand? I tried this in my trial pieces and I couldn't get the effect I wanted. It also meant waiting for the caulking to dry a little otherwise it it had a tendency to sometimes detach from the material in large clumps with whatever was being used to texture it. In the end the sand gave the best result.

Spreading the sand

• Work in Sections: The caulking will dry fairly quickly so it's important to work in small sections.

Patting down the sand to ensure it embeds into the caulking

• Remove Excess Sand: I didn't want to risk dislodging large sections of sand so a gentle lifted and roll up the mat as I went allowing any loose sand to roll off as I rolled it up. I purposely didn't brush over the mat as I wanted to leave as much sand on it as possible for the initial paint coat.

Mat with excess sand removed

• First Coat of Paint: The first coat of paint using the darker colour. I wanted to ensure that a good coat of paint was applied and would also provide some additional adhesion for the sand so I chose to add some PVA glue. I used a ratio of 2 parts paint, 1 part PVA, 1 part water. Since the mat was so large I thought it might be best to see if I could roller on the paint. Bad move! Since I had used Kitty Litter, which essentially is a liquid absorber, as I rolled the paint on they became soft and many started coming off the mat and sticking to the roller. This made in near impossible to actually get paint onto the mat. Below is 2 photos of how far I got with the roller before switching to the paint brush and the other shows the state of the roller when I stopped.

Extent of painting with a roller

Roller with bits of kitty litter stuck to it

First coat of paint completed (Wet Look)

First coat of paint dried

• Second Coat of Paint: The second coat of paint was done less liberally. Not quite a dry brush but enough so that the darker colour still showed through in patches.

Starting the second coat of paint

Second coat of paint completed

• Dry Brush the Yellow Tone: You would have noticed that one of the colours was a yellow tone. This was the third colour used and it was dry brushed all over the mat. The colour allows the mat to have a move vibrant tone. With the dry brushing there was the odd stone or two that came loose but a vast majority didn't so no need to panic if bits do come off. If you have the base colours right the section where the stone comes off will just blend in.

Yellow colour dry brushed on

• Final Sand Colour Dry Brush: The last colour applied was the sand based colour. This really highlights all the texture in the mat. The close up image with the miniatures shows just how well it comes up.

Sand coloured dry brush

Complete painted look next to Italian Allies

• Adding Grass Tuffs to Complete the Mat: The final step was to add grass tuffs to the mat. I wasn't too keen on doing this directly onto the mat as it would have meant a large clean up with any fibres that didn't stick. I chose to make the tuffs using various colours, but sticking to the more dried look rather than the spring grasses. If you can't make them then commercial ones would be fine. Even though I made up quite a few as you can see in the photo below, I actually didn't use that many. I made sure they were quite scattered so its feasible that you'd easily cover a smaller mat with less than 100 tuffs. I found that the straw coloured tuffs tended to get lost on the mat due to their light colour.

Final touches making grass tuffs

Grass Tuffs glued randomly over the entire mat

• Finished Product: I was very happy with the final result and so were the other guys that I game with. The photos below are from the show weekend and you can see that it does mold to the terrain underneath quite well. I did find that there was some creasing where the hills were but it just added to the realism in my opinion and we did pin down some areas to get it to conform closer to what was underneath but the beauty of this being material based was that is was flexible enough to do that and the pins could be pushed through easily and didn't leave any noticeable holes when removed. More photos of the game day have been posted on TMP but I may post some more here on a later post.

Egyptian vs Hitite/Sea People Game of FOG

Game table view from the water side

Some final notes. I used 13 tubes of caulk to make the mat. I didn't weigh the mat but this is quite a large one and I'd imagine others wouldn't necessarily make ones this large. I estimate its really no heavier than 10kg (~22lbs) and for its size I think that is fairly good. Some gamers carry lead around heavier than that. I'd imagine someone's going to ask how the water was done in the above photo. I'll hopefully cover that in an upcoming post.

Post Note: I've had some questions about the flexibility of the mat and yes it is quite flexible. The terrain I use is with modular polystyrene blocks shaped so that I can make hills and valleys or river sections and then place a gaming mat over the top. The next two pictures will give a better idea of how flexible it is. The river section and coast line actually dips away and there are small hills on this layout. You can see in the first photo that the mat contours to the river section quite well. The last photo also shows the mat partially rolled up. It essentially has the flexibility of a heavy canvas mat.

Mat following the contour lines of terrain underneath

Matt partially rolled up to highlight flexibility