All you need to know about filler primer for 3d print (Easy Explanation)

The thing about 3D printing is that you want a perfect finish on your 3D printed models. While painting gives you the last touch, the actual secret behind a perfect finish is the filler primer for 3D print. Don’t know what it is?

A filler primer is a substance that gives your 3D-printed models the necessary exterior they need before painting. Using the primer will ensure the paint job lasts for a longer time and has the smooth finishing that you desire from it.

I am sure this little information doesn’t cut the deal for you. That’s why I suggest diving deep into the article with me to find out everything you need to know about filler primer. Let’s get going.

The purpose of using primer for 3d print

The first thing to discuss here is the use of a primer. Why do you need it, and why should you get it in the first place?

First of all, using the primer gives your 3D models the perfect finish that you want to get on your 3D models. It prepares the 3D model for the paint job. Before you paint your 3D model, you must use the model’s primer. Once you do that, the paint sticks much better afterwards.

Also, if you want to keep the 3D model unpainted, you can do that. Using the primer gives it the flawless finishing you desire on your 3D-printed models.

All this discussion brings up a very common question: Can you paint your 3D models without using the primer? The answer is yes, and you can paint certain 3D print materials without using any primer. Materials like PETG and PLA can continue with the painting process without using any primer.

So, it’s not like you have to have primer for all your 3D-printed models. However, it is always a great idea to have them for the best possible finish on your 3D models.

The process of painting a 3D model and the use of primer

Filler primer is closely related to the process of painting a 3D model. Let’s check out how the primer works out in the painting process of a 3D model and how it impacts the outcome. Here’s how you can flawlessly get the painting job done on your 3D model –


The main goal you are trying to achieve with priming is to get a high-quality look on your 3D model before you even paint it. Using the primer brings up all the imperfections in your 3D model and makes them visible to you.

What’s the point of highlighting imperfections? You can then easily sand them out or fix them using spot putty. As a result, the final 3D model has a glossy and professional look without too many imperfections noticeable to the naked eye.


After priming your 3D model, you can move on to the finishing section. Here, you will mostly think about getting rid of all the imperfections you find after the priming process. Things like rough surfaces, seams, gaps on the model, any strings or residues, lumps, etc.

Finishing involves different processes, such as sanding, spot putty, cutting the residues, removing glue residue, and so forth. You are trying to eliminate everything that can make the 3D model look ugly or unprofessional in this process.

Typically, these two processes are enough for you to prepare the model for painting purposes. But if you want to get the best possible result and best quality in your 3D models, I recommend going for a second coat of primer after the finishing. It allows the 3D print to have much more richness when you paint on it. It also helps create contrast.

Now, after these, you can move on to the painting process, an entirely different topic of discussion.

Steps for priming

You might struggle a little bit with the priming steps as a beginner. Don’t worry at all, because now, I will be listing all the basic steps for priming your 3D print. They are straightforward to follow steps so you won’t have any trouble even as a beginner.

Here are the steps you should follow along –

  1. The first thing you have to do is remove any support you may have on your 3D model. You can use cutters to remove them, or you can remove them by hand. Using knives or cutters works best when dealing with delicate 3D models.
  2. After removing the supports, you have to sand the areas properly. Sanding helps you remove any mark from the supports the 3D model may have gotten. You can use sandpaper or a rotary tool, depending on the project you are working on.
  3. In the next step, you have to sand the surface of your model. Make sure you are smoothening the model’s surfaces so you can use the primer properly without any issues.
  4. Next, mount your 3D model in a dowel where you prime it and paint it easily. Mounting the model makes the process very easy and convenient for you.
  5. Once you mount the model, you can start washing it on the surface level. Doing this will eliminate any dust you may have had on the model.
  6. Now, take a towel and wipe the 3D model to dry it out.
  7. You can start working with the primer when the model is dried out. First of all, you will need to mix your primer. Always remember that you don’t need to shake the primer can. You must gently swag it in a circular motion to mix it. Do this for about 2 or 3 minutes.
  8. Around this time, you can start spraying the primer on your 3D-printed model. When you are spraying, make sure that you are doing it from all angles. Rotating the part while spraying the primer helps you cover up most of the areas and doesn’t leave any gaps. This is the first coat of the primer.
  9. Check up on the first primer coat on your 3D model and look for imperfections. You will need to get through the finishing process if you see any imperfections. Here, you will be getting rid of those imperfections.
  10. Lastly, you can go for the second and final coating of the primer to give your 3D model that professional finishing touch. The second coating can help your 3D model look more pristine after painting.

These are the basic steps you must follow to prim your 3D-printed model.

Best primers you should try out.

Whenever you get into all these things, it’s hard to find products you can rely on. To make it easy for you, here are some of the best primers to look out for in your 3D printing projects. Check them out –


Most of the advanced 3D printers out there recommend using Rust-oleum for your 3D print priming purposes. This primer can give you the perfect smooth finish after sanding your 3D model. It also helps fill the model’s imperfections without too much effort. Just make sure to use the primer in a well-ventilated area.


When you are using plastic as your 3D print material, Krylon is the perfect primer for that purpose. It works great on plastic surfaces and provides quick and strong adhesion. You can get good results when you use this primer.


Do you work with a lot of ABS material? Then, I would say this is the primer you should pick. It provides you with proper coating on the 3D models. It also helps prevent the model from cracking or tearing after using the primer.

Aside from these three, there are several other choices that you can find out there. But if you don’t want to go through the hassle of looking for a good option, these are the ones you can rely on. They are perfect for specific purposes, and the quality is something you can rely on for all your choices.


Wrapping it all up, filler primer for 3D print is something you will need to be concerned about for sure. Especially when you care about the looks and finish of your 3D printed model, you have to go with the correct primer.

I tried to give you all the information you need regarding filler primer in this article. You won’t have any struggles or trouble with it. Just make sure to choose the perfect primer option for your project. Now that you know the best possible primers, you shouldn’t have trouble choosing one.


Leave a Comment