Introduction: How to Paint and Finish 3D Printed Props

Hello there!!!

I'm writting this Instructabe to show you how to give the realistic aspect you've ever wanted to your 3D printed props and models. You'll learn about several painting techniques, as well as step by step instructions to simulate different materials in your props, from rusted iron to shining glass.

If you wanna know all this awsome techniques, continue reading this Instructable, and you will became the next Prop Master!

Step 1: Tools and Materials You'll Need

Here is a list of materials and tools we will use in this Instrctable.

There are no links or specific brands because the vaste majority of them can be found in every craft store or hardware store. The materials are divided depending in what type of effect they are going to be used in, as well as a "universal list" were some basic materials which can be used in any technique are lised. Due to this, some materials are repeated several times, so you don't need to buy them twice.

Basic tools:

  • Paint brushes (different sises and forms)
  • Crafting knife (as Sharp as posible)
  • Sandpaper with different roughness
  • Sponge
  • Scissors
  • Masking tape
  • Paper towel
  • A plate with water

Basic materials:

  • Body filler
  • Spray paints
  • Acrylic paints
  • Transparent varnish (glossy or matte)

Specific materials:

Fake rust:

  • Wood glue (or any kind of crafts glue)
  • Fine sand
Old metal:
  • Silver spraypaint
  • Toothpaste
Other materials and tools (optional)
  • Security tape
  • Glow in the dark paint
  • Electric tools

Step 2: First Step: Preparing Your Prop

(This step explains how to glue, sand and smooth a 3D printed prop. If you already know how to do this, you can jump to the next step)

Before starting making your prop look realistic and awsome, you will need to prepare it for the paiting process.

First of all, if your prop is been printed in different pieces due to its size or complexity, and this pieces don't have any type of movement in the final prop, you should glue all the pieces together, using an specific 3D printed pieces speciall glue, or using any type of contact cement that you have near you. Yuo have to make sure that the glue you're using isn't elastic, because you don't want your prop to bend in the middle of a ComicCon, while everyone is admiring your Halo Master Chief laser gun or something as embarrasing as this. You should also read the glue's instructions properly to make sure that the glue you're using isn't toxic. If necessary, wear a safety respirator.

Once your prop has its final shape, you should cover i t with a fine layer of body filler. This body filler can be in form of spray or brush Paint. You can use an specific for 3D printed pieces body filler, like XTC-3D; or you can use some buolding body filler you can find in any hardware store. You have to make sure that the body filler isn't very dense, and that it can be applied into the type of plastic you prop is made.

After the body filler is dry, you have to sand all the piece using some sandpaper. A 200 roughness sandpaper will be a good one to start sanding your piece. After the sanding, you should cover the prop with other layer of body filler, and sand it again with a lower roughness sandpaper. You will need to repeat this steps until your prop is as smooth as you want.

Once you are fine with the prop's aspect, go to the next step.

Step 3: Second Step: Primary Colours

If you are reading this, is because you've just completed the tedious process os priming and sanding your prop. Probably you are tired, but you have in your hands a smooth and plain prop. If you want your prop to be boring and monochromatic, congratulations, you've fnished the process. If you are not happy with your plain and sad creation, continue reading. Here is were the magic that gives life to your creations starts!!!

Lets start from the beginning. Normally, all the props have a different base color than bodyfiller's one, so its time to paint your piece. In this point you should make a decission. If you want your prop to look like an old metal piece, wich has parts were the original paint has dissapeared revealling the silvered metal that was covering, you should jum to the "Simulating old metal" step. If you are not interested in giving your prop this aspect, I invite you to continue reading.

It's time to give your creation the first layer of color. This Will be the base color, that will cover the bigger surface. In this step, i highly recomend you to use a spray paint. They are cheap and can be used to cover big surfaces in a short period of time. You can choose the color you prefer, and you can always look for external references to show to your nearest paint shop employee, and he Will help you choosing themost similar colour. Also, if your prop has the same color that the body filler you've used, I recommend you covering the prop with a layer of that colour spaypaint, because its easier to apply different types of paint over a sparypaintlayer than over an industrial body filler.

You should always remember that, if you are using spraypaints, you have to work in a ventilated área, being aware of not painting food or things you are going to put in contact with your body. You should also wear a respirator and safety glases. I cant grant you that spraying Paint into your eye by mistake isn't a funny experience.

Once your prop has that shiny colour that represents it, you can go to the next step.

Step 4: Third Step: Giving Details to Your Prop

Now you have a shiny and almost ready prop, but normally, almost every cosplay object has at least two or three colour that gives details and realism to the prop. This is the step whre you shou show to the world your painting abilities, or at least look for someone who isn't as horrble as you while having a paintbrush on its hands.

When you are applying a second colour to a prop, you don't want the parts that you've alrady painted to get covered by tha new colour. First of all, you should cover the parts you don't want to be repainted with masking tape. If the áreas to cover are very big, you can also use paper towels and glue them to the prop with masking tape in the borders and difficult areas. This could become a very tedious part, but I can grant you that, the more patient you have covering all the details, the better the final result will be. Having said that, I can't give you more detailed advice of wich part should be covered, because every prop is different. The only thing I can say you is to be patient and prepare to have a good time olaying with scissors, paper towels and masking tape.

Once you've covered all the parts you dont want to be painted, you can apply the second layer of Paint. In this step, I suggest you to use acrylic Paint. It's easier to apply using a paintbrush, and you can mix different colours to get the exact colour you are looking for. If after one colour you want to apply another one different, you should repeat the masking process again. You can repeat this as many times as you want.

When your prop has the colours you want, it's the most magic moment during all the process: removing the masking tape. While you remove the masking tape carefully, the colours and details of your prop will become visible, and your prop will come to life. At this point, you should apply a layer of transparent varnish to your prop, to avoid it to be damaged in the future.

At this point, your prop is finished and you should be very proud of it. It's time to show it to the world, but this isn't the end. If you want to give to your prop a more realistic aspect, or you want to learn different techiques for your future works, I've created a few more sections for you. Continue reading if you want to learn how to créate fake rust in your props, or how to simulate that your creation has suffered during his life, so its dirty and worn.

Step 5: Extra Step: Simulating Use in Your Prop

If you are reading this is because you thing that your prop looks very clean and perfect, like if it has just been released from the producting line... and you don't like it. If so, you are lucky, because in this step you'll learn how to dirty your prop tho make it look that it has just survived to a chaotic and dangerous battle in a swampy planet. Or that it is a magic sword that has been buried for years by an ancient wizard, or… You see, with this technique you can give realism to your prop's background.

This technique is very easy. It takes longer to explain it than applying it to your prop. You'll only need some acrylic paints, preferably dark colours like brown, black or grey, a cup with water and some paintbrushes.

Firstly, you have to mix the darker color you have with a tiny amount of water. Then, you have to apply it with a paintbrush in the areas you want to be dirty. Without waiting the paint to dry, you should take a wet paintbrush or papel towel and pass it gently over the painted areas. And that's all. You'll probably need some practice, but after a while you'll notice your improvements, and finally you will have an awsome and dirty prop to show to your friends.

Step 6: Extra Step: Simulating Rusted Metal in Your Prop

You've learnt previously how to recreate dust and dirt in your props to simulate that they have lived an exceptional adventorous life, but maybe your prop background is completely different. Your prop could have been underwater instead than buried, and in this case your prop would be covered in a realistic brown oxid. This is exactly what we are going to learn here.

In this step you'll need some scholar glue and a cup of tiny sand. First, you should mix some glue with the sand, until you get a putty that is maleable enough to make forms with it. It mjst have more glue than sand, because it is the one who will join to the prop's surface. When you have your mixture done, you'll need to extend it in the parts that are going to be rusted using a paintbrush. Wait until it gets dry and you'll find a rough Surface very similar in texture to normal oxide's. Finally, you should take your brown and red acrylics and paint it until it gets the rusted tone that you want.

Step 7: Extra Step: Show the Metallic Inside of Your Prop

This is the step I've mentioned before, when talking about the principal color of your prop, so it needs no extra explanation.

For this step you'll need some toothpaste and your finger. Yes, you're going to get dirty here. This is one of the funniest parts of the process. The only thing you have to do is put some toothpaste onto your finger and expand it gently in the places you want not to be covered by the principal color. You can also use a paintbrush, but it's easier (and funnier) doing it with your finger. Once you have finished, you can spray the first layer of principal color as explained in the second step. You have to take care not to move the toothpaste before spraying the Paint, because the parts covered by toothpaste are the ones where the spray Paint wont stick to the prop, revealing the metallic inside of it. Finally, when the spray paint is dry, you can easily retire the toothpaste with a wet paper towel. Then, you can return to step three and continue with the painting process.

Step 8: Final Step: Protecting Your Prop

You are done. You have just created an awsome and realistic prop, and you're waiting for the next ComicCon to show it to everyone. But I'm completely sure that you don't want to prop to break or damage at all. To avoid this, I suggest you to cover your prop with a layer of spray varnish. You can also use a normal brush varnish, but you Will risk to remove or destroy part of your work. And now you're really done! Your awsome prop is ready to use and amaze everyone you show to!

But, despite this step title ("final step"), this isn't the end. It's only the end of this Instructables. You can always add more things to your creations, like leds or sound effects; or you can apply different thecniques to your future proyects, to make them look more realistic and expectacular. The only limit is your imagination.

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