How to make markers for Terraforming Mars - Oxygen, Heat, and Generation tracks.

Terraforming Mars was my entry into hobby board gaming, so it carries much of the blame for why I now own 4 new shelving units and a lot less savings (joking, it came out of checking). No regrets, though! This hobby has been a wild ride and has provided countless hours of fun, many of which Terraforming Mars (TM) can account for. 

When I first started upgrading my games I was taking on these huge projects in which  I had to make a ton of something, like my Scythe resources or my Spirit Island tikis. When I thought about upgrading Terraforming Mars, it was a much less daunting endeavor. The resource cubes didn't really need upgrading, and 3D tiles were something I assumed I'd buy (although I ended up making those also). 

So it was clear that a simple set of markers for the Oxygen, Heat, and Generation tracks were the way to go. 

They came out nicely and they have a great tactile feel. As a plus, I enjoy the generation marker so much that I never forget to advance it anymore! 


This project is a great one for beginners! It's mostly simple shapes with the exception of the heat marker, which you can experiment with until you get a result you like. 


Time: 1-3 hours depending on skill

Cost: $10-20 if you're starting fresh, but you will have LOTS of clay left over (and some tools). The actual cost of clay is closer to $1.


  • 9 colors of Polymer Clay (white, blue, red, yellow, orange, black (optional) and 3 colors of your choosing for the generation marker - I used gold, bronze, and silver). I use Premo! brand, but you can use other polymer clays. Alternatively, this sampler pack is a great way to get started!
  • 3/4 inch round clay cutter
  • 1.5 cm round clay cutter - you can use a marker cap
  • Clay or Fondant roller. I bought this one on sale, but you can also use a hard water bottle like a Nalgene.
  • Gloss varnish and small paint brush
  • Razor blade
  • Non-permeable work surface; I use a dry-erase board
  • Silicone shaper (optional) 
  • Deck of cards, or a pasta machine

Total # of Game Pieces: 3

Don't have time to make them yourself?

You can purchase these here!


Let's get started!

White Bases

*Note: white clay picks up every speck of lint/dirt, so make sure your hands and surface are incredibly clean - lint roll your hands maybe?

Start by taking a bit of white clay and roll it out to a thickness of about 5 playing cards (for more explanation on how to do this, check out the 1st step on my Scythe Encounter Tokens article).


Use your marker cap or 1.5 cm cutter to cut 1 circle base. This will be for your heat marker, so it just needs to be the right size for the heat track.


Use your 3/4 inch cutter to make 2 circle bases.


Use a razor blade to carefully move the bases out of the way.


Bases are done. That was easy!


Generation Marker

The generation marker is the easiest of the three, so we will start here. Essentially we just need three columns and three spheres, each progressively shorter and thinner than the last, to make 3 different sized people. You can use any colors you like! 

I like to start with my tallest person. Roll out a piece of clay so that it is about 6mm in diameter.


Using a razor blade, cut it to be about 1.3cm long and flat on both ends. When you make your cuts, you may need to roll the blade back and forth like a saw to prevent getting a flat side on your column.


Form a ball to make the head. You can experiment with different sizes, but mine ended up being about 8mm in diameter.


Slightly flatten your sphere on one side, and place it on top of your column, pressing down hard enough to adhere the clay, but not hard enough to deform the column.

NOTE: You can put this on the white base now, or you can wait till all of the people are finished!


Next, we will make the second tallest person. Roll out a piece of clay about 5mm in diameter.


Cut it to be about 1.2cm long and flat on both ends. Again, be sure to use the "sawing" method when making your cuts.


 My middle-sized head came out to be about 6mm.


In the same way, adhere your sphere to the column.


Unfortunately I forgot the picture for the column of the smallest person, but it ended up being about 5mm in diameter and 9mm long. 

The sphere came out to about 5mm in diameter. 


Adhere the sphere to the column, and you have finished your last person!


Add each of your people to one of the 3/4 inch bases in a triangular shape. Press each down lightly to adhere to the base. 

Use a razor blade to carefully transfer this to a baking sheet.

Ooh, shiny!


As a plus, here's the first one I did with different colors (dark purple, orange, and lime green).


Oxygen Marker

This one looks a bit more difficult than it is. The hardest part is the O2 wording on the front, so if you wish to skip this challenge, you can simply use a Sharpie to write O2 AFTER the clay has baked. This will work perfectly fine!

Begin by rolling out a column of blue clay a bit more than 1cm in diameter.


Cut the column to be 2 cm long and flat on both ends, using the "sawing" technique to avoid a flat side. Smooth out one side so that it doesn't have any razor marks.


Place your column on the second 3/4 inch base. Press down gently, but be sure it adheres somwhat to the base.


Next, roll out a small piece of blue clay. This should be about 4mm in diameter.


Cut this to be only 3mm long. Your piece should be a short stump.


Place the blue stump on the center of the large column, pressing lightly to adhere.


Take a tiny bit of white clay and roll a ball about 4mm in diameter.


Use your finger to press down lightly, flattening the ball slightly into a thick disc.


Place the disk on top of the blue stump, pressingly lightly to adhere.


Our cap is finished, now we need a hose. Roll out a thin white rope, about 2mm in diameter, and about 2.5 cm long (the photo shows 3cm, but you should only cut 2.5cm).


Attach one end of the hose to the blue stump on top.


You can use a silicone brush or something similar to better adhere the hose.


Take a small piece of red clay and form a ball abut 4mm in diameter. 


Attach the red ball to the end of the white hose. The red ball should be warm from forming it in your hand, and should adhere to the hose pretty easily.

Wrap the hose down along the side, pressing gently until it reaches the base, then wrap it along the front of the base of the tank. (*I forgot to take a picture of this, but you can see it a couple pictures below.)


This step is only if you want to make the O2 lettering 3D. You can skip this step and make your life a lot easier by using a Sharpie AFTER you've baked the clay. 

Otherwise, make a thin rope of black clay, 1mm in diameter or less if you can. You don't need a full 7mm, but it will help to have some extra rope to hold onto.


Place the end of the rope where you want the left side of the 'O' to be, and begin wrapping the rope in the shape of an O. Gently press the clay against the blue canister as you go to adhere.

Continue shaping.

Once you get to the connection point of your 'O,' use your razor blade to carefully cut the black rope without cutting into the blue canister. Gently adhere the ends of the O together.


Start placing the top of your '2' near the bottom right of the 'O.' Start forming the shape of the 2, gently adhering he clay as you go.

Continue the shape. You will likely need to try this a couple times.

Cut your rope where you want the '2' to end. Press gently to adhere. 


Carefully use a razor blade to move your Oxygen marker to the baking sheet.



Heat Marker

This marker is the most difficult. Fire is very fluid, so the process in which I form the clay is different each time and takes some eye to get right. As long as you have an idea of what look you want, you should be able to follow these steps loosely to achieve it. 

Begin with two thick pieces of red and orange clay (slightly less orange is my preference).

Begin rolling the red and orange clay together with your hand so that it starts to blend.

Next take a much smaller and thinner piece of yellow clay, and start rolling this in as well. 

Continue rolling and combining until you get the effect you like. In my case, I ended up folding my long rope in half a couple times, continuing to roll after each fold. This yields much finer lines.

Once you have your desired effect, roll the clay gently so you have a rope about 7cm long and about 5-6mm in diameter. 

Roll the ends out so they are pointed.


This is where the process becomes pretty loose, so if you feel you can form the clay more easily your own way, do it!

In this case, I started with a 'U' shape, with the left side shorter than the right.

Then I twisted the right side into a loop, so that the end was coming toward me.

Then I moved the end of the loop to be behind the left side of the U (the other end). 

I also began crossing the left side of the U to the right (still in front).

I pulled the original looped end up slightly, stretching the clay to elongate it slightly.

I also elongated the end that is now furthest right and began shaping the tip to face upwards and to the right a bit more.

Once the bottom of the fire was established, I placed it on the small, white base (1.5cm). I pressed gently in various places around the base of the fire to adhere it to the white base.

I finished shaping the tips of the clay to achieve the form I liked. I settled on this.


Once you like your fire's shape, you can carefully use a razor blade to transfer it to the baking sheet.


Last thing I like to do is varnish the Heat marker only. It looks much better with a shine, but the others look better matte, in my opinion. 




The baking time for these will be slightly different. The Oxygen tank is the thickest, and in my experience takes about 1 hour to bake(30 minutes per 1/4 inch for Premo - 275 degrees F). Most clay baking times are per 1/4 inch, so follow the instructions of your clay based on this.

You can start baking everything at the same time, and just remove the generation and fire markers before the oxygen tank (at about 30 minutes for Premo).  

I like to put my pieces in an ice bath immediately after removing from the oven, but this is not required.

Don't have time to make them yourself?

You can purchase these here!


About the Author

My name is Alee! I'm an avid board gamer who loves to craft. I started upgrading my games in various ways and stumbled upon polymer clay 4 months ago. Since then I've been making tons of board game pieces and have fallen in love with the outcome. 

When I'm not playing games or crafting I'm typically out rock climbing, backpacking, or watching space launches. For work I'm a molecular biologist, so I love science (of all kinds). 

What's my favorite game? #X-ODUS: Rise of the Corruption


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Owner8 months ago

That O2 can keeps giving me "Among Us" character vibes haha. Beautiful stuff again too!

7 months ago

Dude so good.. I was thinking the same thing lol

8 months ago

I see it! Fun!

Supporter7 months ago

Love it! Nicely done!

7 months ago

i love these articles, thank you.

have you considered making How- to videos? i know if would be a lot more work, but i can promise at least 1 person will watch. 

7 months ago

Yes I have, but I typically work at night when the lighting is horrible, so I've been avoiding it. I think it would be cool though:)

Owner7 months ago

Wait.. you made 3D tiles too??

7 months ago

Haha, yeah! I made ocean and greenery tiles. They aren't super consistent or professional looking, so I don't sell them but they add a lot to the gameplay. 

I added cows to some of them...because I like the idea of cows on Mars.

Premium User8 months ago

As always, great work!

7 months ago

Thanks, cbrady!

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