Introduction: Tree Planting Paintballs

Trees have the potential to remove a significant amount of carbon from the atmosphere, reducing the impacts of climate change. However, many people don't want to make the effort to plant them. Also, some areas are difficult or dangerous to access to plant trees. Tree Planting Paintballs make tree planting easy and fun. Using easy to find materials, coupled with a relatively inexpensive paintball marker, anyone can help reverse climate change.

I decided that my project should:

  • be easy and fun to make
  • use commonly available materials
  • be relatively cheap to make

Tree Planting Paintballs can use any type of plant seed, but trees remove the most carbon compared to other plants. Also, localised native tree seeds will have the best chance of survival from initial planting.



Paintball marker (0.50 or 0.68 calibre)

3D printer (or use Shapeways if you don’t have access to a 3D printer)

Paper shredder (optional)




Food dehydrator (optional)


Tree seeds

Scrap paper (note – not glossy paper. Newspaper or used printer paper best)

Cornflour (corn or maize starch)

Approximately 11g of filament (if you have a 3D printer)

Step 1: Order the Materials

here are some amazon links to all of the tools and materials I used. if you don't want to wait for shipping, then you can buy them locally

Step 2: Print the Parts

Next step is to print the mould for shaping each seed paintball. I printed mine on my Ender 3, but any printer should work. Use the 0.68 for a 0.68 marker and the 0.50 for a 0.50 marker. I made these using Tinkercad. If you don't have a 3D printer use a service like Shapeways or ask a friend.

Step 3: Shred the Paper

Essentially, we are making papier-mache. You can rip it by hand, but if you want to do a lot, or do it quickly, you can use a simple office paper shredder. Alternatively, you could use a craft knife if you don't have a shredder.

Step 4: Make the Paper Mixture

Add some of your shredded paper into your blender jug with a bit of corn starch. Add a little water and blend. Slowly add water until it forms a paste. Blend until smooth. Place the cheesecloth over a bowl or in a kitchen sink. Pour the paper mixture onto the cheesecloth. Squeeze the water out of the cheesecloth until the mixture forms a clay-like consistency. Be careful to not squeeze too hard or you may tear your cheesecloth. If you have any leftover add it to a jar with some water and store in the fridge.

Step 5: Mould the Paintball

Take the bottom half of the 3D printed mould and fill with the squeezed paper-clay mixture. Add 1-3 seeds into the middle then put some more paper-clay mix on top and press down. Now put the top mould on and clamp both sides together in the vice as tight as possible. Leave for 5 minutes.

Step 6: Dehydrate Your Paintball(optional)

Gently remove the paintball from the mould. Place into the dehydrator for a few hours until hard. If you don't have a dehydrator then leave for a few days until hard. Now your paintball is done and ready to be fired!

Step 7: Fire Your Paintball

Make sure your paintball marker is
empty (has no paintballs in it). Now add your seed paintball into the magazine or hopper. If it doesn't fit, then put the paintball down the barrel. Now simply aim for the location you want to plant your tree and fire!

it pays to fire the paintballs when you know rain is coming as there is no point in the seed sprouting and trying to grow without some moisture. I tend to keep an eye on the weather forecast and fire them when there is rain coming.

Step 8: Wait

When it next rains, the papier-mache will absorb the water which will make the paintball start to fall apart. The water will tell the seed to start sprouting and the tree will grow. The rest of the paintball is fully biodegradable, and the paper will help the seed grow.

STEM Contest

Participated in the
STEM Contest