3D printing in resin: what it is and how it works, my guide for makers 🚀

Hey there, maker! If you've ever been blown away by a miniature with insane detail or seen a prototype with a perfectly smooth surface, you were almost certainly looking at a resin 3D printing piece. It's, to put it simply, liquid magic that transforms into solid objects with jaw-dropping precision, all thanks to light.

It's the secret to achieving those ultra-fine details that drive us crazy with other methods. In this guide I'm going to share everything I know, just between us, so you can stop being intimidated by this technology and start creating.

What is resin 3D printing and why you're going to love it

Let's be straight here. My goal is to tell you what this technology is and why it has changed the game for so many of us. By the time you finish reading, you'll know whether resin is for you and how you can take your first steps. I've got you covered!

Imagine you have a bottle of a very special liquid (the resin). Now picture that, thanks to UV light controlled down to the millimeter, that liquid hardens layer by layer, in an almost imperceptible way, until it forms a solid object. That is, in essence, resin 3D printing.

This technique is the undisputed queen when what you're after is a spectacular level of detail. It's what makes the difference between a figure with a blank face and a miniature where you can count every buckle on the belt. If miniatures for wargames, jewelry, or prototypes with flawless finishes are your thing, you're going to fall in love, I promise you.

To give you an idea, take a look at the variety of resins for 3D printers that exist. In my experience, there's a whole universe beyond the typical grey resin.

The big difference from FDM printing (the filament one)

You've surely seen 3D printers that work with rolls of plastic, the FDM ones. They build pieces by depositing threads of melted plastic, like an extremely precise hot glue gun. They work great for large, functional pieces, no doubt about it.

But when it comes to detail, resin plays in a different league. Why?

• Surgeon-like precision: Light is able to solidify tiny areas, achieving a resolution that filament simply cannot reach.

• Surfaces as smooth as silk: Layer lines are almost invisible. The result is a professional finish that comes out that way straight from the printer.

• Materials for every need: There are resins with very specific properties. For example, an ABS-like resin for harder pieces or a water-washable resin, which makes your life so much easier when it comes to washing.

In this guide we're going to break down the process from start to finish. From choosing your first bottle of resin to holding your creation in your hands, already cured and ready to show off. I'm not going to leave you on your own! I want you to stop being intimidated and start creating pieces that leave people speechless. Ready? Let's go!

How liquid magic works: SLA, DLP and MSLA technologies

OK, so we already know what resin 3D printing is, but... how on earth does a liquid become a solid, detailed object? This is where things get really interesting. Not all resin 3D printers work the same way, so let's break down the three technologies that drive this world: SLA, DLP and MSLA.

And don't let the acronyms scare you. I'm going to explain it like we're in the workshop with a coffee in hand, so you can pick it up in no time.

SLA (Stereolithography): the laser artist

Imagine an artist with a surgeon's steady hand and an ultra-precise laser pen. That's how SLA (Stereolithography) technology works.

A UV laser beam literally "draws" each layer of your piece onto the liquid resin. Point by point, line by line, with millimetric precision. It's the original technology, the grandmother of them all, and it remains the undisputed queen for achieving incredibly smooth surfaces and breathtaking detail.

• The good: The quality and precision are spectacular. In my experience, the surface finish you achieve is practically unmatched.

• The bad: It's the slowest of the three. Since the laser has to travel across the entire surface of each layer, the process takes quite a while, especially on large pieces.

DLP (Digital Light Processing): the cinema projector

Now, let's shift gears. Think of DLP (Digital Light Processing) technology as a miniature cinema projector. Instead of a laser that draws, a UV light source projects the complete image of the layer onto the resin. Flash! And the entire layer solidifies all at once.

This makes it much faster than SLA, especially when printing multiple pieces at the same time. The time per layer is the same, regardless of whether there's one or ten objects on the build plate.

• The good: The speed. It can cure entire layers in just a few seconds.

• The bad: Resolution depends on the projector's pixels. It's like a photo: if you zoom in too much, you can end up seeing the pixels (which in 3D we call voxels), which can sometimes show up in fine details along curved edges.

MSLA (Masked Stereolithography): the queen of balance

And finally we come to MSLA (Masked Stereolithography). This is the technology used by the vast majority of affordable 3D printers you see on the market today, and for very good reason. You could say that MSLA is the clever child that learned the best from both parents.

It uses an LED matrix as a UV light source and, right above it, an LCD screen that acts as a mask. This screen only lets light through in the areas that make up the layer, blocking the rest. So, just like DLP, it cures entire layers all at once.

In my opinion, MSLA technology offers the best balance there is between speed, detail quality and cost. It's the one I almost always recommend for anyone who wants to get started in this world or take a quality leap without breaking the bank.

This technology has been the true driving force behind making resin 3D printing much more accessible to everyone. If you want to dive even deeper, I recommend taking a look at my article on how a resin 3D printer works exactly.

The popularity of these technologies, especially MSLA, is undeniable and has helped make resin 3D printing one of the preferred options for a huge number of projects.

Comparison of resin 3D printing technologies

To make everything crystal clear, I've put together a table that summarizes the key differences at a glance. This way you can see which one best suits what you're looking for.

As you can see, each technology has its strong point. While SLA remains the option for maximum precision, MSLA has crowned itself as the all-rounder thanks to its incredible balance of quality, speed, and price.

Your resin 3D printing workflow step by step

Let's get to it, maker! Now that you understand the theory behind the magic, let's move on to the most fun part: the practical process. I'll walk you through the entire workflow step by step, so you know exactly what to do from the moment you have a 3D file to when you admire your finished piece.

I've seen many beginners get stuck at this point, but don't worry. I've broken it down into four key phases that, once you master them, will turn you into a true resin pro.

1. Model preparation and slicing

Everything starts at the computer. You can't simply send a 3D file to the printer and cross your fingers. First, you need to prepare it using a program called a slicer. The most popular ones, and the ones I use myself on a daily basis, are Chitubox and Lychee Slicer.

At this stage, your mission is to:

• Orient the part: Placing the model at the correct angle is essential. This helps minimize support marks and ensures it adheres properly to the print plate.

• Add supports: This is the big secret! Supports are like small scaffolding that holds the part in place while it prints, preventing it from falling or warping. Placing them correctly is an art that improves with practice.

• Adjust settings: This is where you define the thickness of each layer and, most importantly, the exposure time. This is the time the UV light illuminates the resin to cure it. An incorrect time can completely ruin the print.

Once everything is ready, the slicer cuts the model into hundreds or thousands of images (layers) and generates a file that the printer can read.

A tip from Mr Resin: Don't stress about supports at the beginning. The programs usually have an automatic function that works quite well to get started. Use it as a starting point and then adjust manually if you see that any area needs more support.

2. The printing process

With the file ready on the USB drive, it's time to turn on the machine. But before hitting the "Print" button, you need to run a few quick safety and preparation checks.

Here's my personal checklist:

1. Check the resin tank (VAT): Make sure the FEP film on the bottom is clean, free of any cured resin residue from previous prints and free of deep scratches.

Now you're ready — insert the USB, select your file on the screen and... let the magic begin! The 3D printer will start lowering the build plate and curing the resin, layer by layer.

As you can see in the chart, although the principle is the same (curing resin with light), the MSLA method has so optimised the process that today it is the ideal option for most of us due to its speed and efficiency.

3. Washing the part

Once the 3D printer beeps to let you know it's finished, the part you take out is covered in liquid, sticky resin. Don't even think about touching it without gloves! This step is key to achieving a clean, professional finish.

The goal is simple: clean off all the resin residue that hasn't been cured. You have two main options:

• Isopropyl Alcohol (IPA): The classic method. You submerge the part in a container of IPA and gently agitate it, or use a soft brush to reach all the nooks and crannies.

• Water-washable resin: My favourite option for keeping things simple! If you use a water-washable resin, you can clean the part directly under the tap. It's much more convenient, safe and eco-friendly.

In my experience, a washing and curing station (the famous Wash & Cure machines) is a total game changer. These are machines that carry out this process automatically, quickly and much more cleanly.

4. Final curing

You're almost there! After washing and thoroughly drying the part, you'll notice it's still a little "soft". Even though it may seem solid, the polymer chains haven't fully formed yet. It needs one final push to reach its maximum hardness and mechanical properties.

This last step is called post-curing, and it simply involves exposing the part to a UV light source for a few minutes. You can use a dedicated curing machine (such as the "Cure" part of Wash & Cure stations) or even leave it in the sun, although the result is less consistent.

This final curing is what ensures your part is truly strong and durable. Skipping it is one of the most common beginner mistakes I see. A poorly cured part can be brittle and warp over time. Don't risk it!

The universe of 3D resins: what types are there?

Choosing the right resin is just as important as having a good 3D printer, friend. It's the raw material of your creation, and each type has its own personality and a different purpose. Printing a miniature for a display case is not the same as printing a mechanical part that's going to take a beating!

I've got you covered. Let's dive into the universe of different resin types so you know exactly which one you need for each project. Let's get into it!

Standard or basic resins

If you're just starting out, this is your resin. Standard resins are the most common and affordable. They're perfect for learning, calibrating your 3D printer, and for parts that won't undergo much stress, such as decorative figures, busts, or display miniatures.

The finish is good, the level of detail is more than decent, and they're easy to use. It's the ideal starting point for any maker.

ABS-like resins for greater durability

This is where things get serious. If you need your parts to withstand impacts, torsion, or rougher use, ABS-like resin is your best ally. I've thoroughly tested these resins and their durability has genuinely impressed me.

What I love most about ABS-like resin is its durability. It's ideal for functional parts, prototypes that will be handled, electronics enclosures, or even action figures that are going to have "battles" in the real world. They hold up far more than people think!

They're a bit more expensive than standard resins, but the investment is absolutely worth it if durability is a priority for you.

Water-washable resin: the most convenient option

Let's be honest: cleaning parts with isopropyl alcohol (IPA) can be a hassle. That's why water-washable resin is a genuine godsend. As the name suggests, you can clean printed parts directly with tap water.

• Less odor: They generally have a less intense smell than traditional resins.

• Greater safety: You avoid handling and storing large quantities of flammable alcohol at home.

• Convenience: The post-processing workflow becomes dramatically simpler.

In my experience, they're perfect for those who print at home and want a cleaner, more straightforward workflow.

High-definition resins for maximum detail

Are you a detail obsessive? Do you want to see every last hair of your D&D dwarf's beard? Then you need a high-definition resin, also known as 8K or 12K resins. They're formulated to work with the latest-generation 3D printers and get the very most out of them.

They're the number one choice for jewelry, dental models, and of course, competition miniatures. If your goal is absolute perfection, this is your resin.

Other specialized resins

The world of resins doesn't end there. There are many more options for highly specific projects:

• Flexible resins: For creating parts that can bend or stretch, such as model tires or protective cases.

• Transparent resins: Ideal for creating water effects, glass elements, or parts that need to let light through.

• Castable resins: Used in jewelry-making to create molds that are then burned out in a kiln without leaving a single trace of residue.

The growth of this sector is unstoppable and innovations keep on coming. Understanding the properties of each resin is essential, and if you want to go deeper, I recommend reading my article on what 3D resins are and their characteristics.

Resin vs. Filament (FDM): the great maker battle

We've arrived at the million-dollar question, the one every maker asks sooner or later: resin or filament? As someone who has burned hours (and more than a few fuses) with both technologies, I'm going to give you my most straightforward take. Forget about looking for a winner; this isn't about which one is "better", but about which is the right tool for your project.

Think of them as two different worlds, each with their own superpowers. FDM printing, the kind that uses plastic rolls, is your workhorse: robust, reliable and perfect for large, functional parts. Resin, on the other hand, is the surgeon's scalpel: precise, detail-oriented and capable of creating genuine works of art in miniature.

The devil is in the details (and in the finish)

There's no debate here, friends: resin wins by a landslide. While with FDM you'll always see layer lines and often have to sand and fill to get a smooth surface, with resin the layers are practically invisible.

• Resin: Offers jaw-dropping resolution, capturing tiny details like the texture of fabric, a facial expression or minuscule engravings. The finish is smooth straight out of the 3D printer.

• FDM: Ideal for quick prototypes where detail isn't the top priority. Layer lines are part of the game and, while they can be disguised, they'll always be there.

To give you an idea: a 28 mm miniature printed in resin will show even the buckle on a belt; in FDM, you'll be lucky to make out the belt at all.

Strength and applications: beauty or brute force?

This is where FDM flexes its muscles. If what you need are parts that can take a beating — brackets, gears, housings — filaments for 3D printing like PETG or ABS are usually the best option. These are engineering materials designed to be tough and durable.

Watch out! This doesn't mean resin is fragile. A well-cured part made from a good ABS-like resin is surprisingly strong. But if absolute hardness takes priority over detail, filament usually has the edge.

Post-processing: the work after the work

Both methods require a little extra work once printing is done, but the tasks are very different:

• Resin: Post-processing involves washing the part with alcohol (or water, if you're using water-washable resins) and then curing it with UV light. It's a process that calls for gloves, good ventilation and a bit more care.

• FDM: Here the main task is removing supports, which sometimes leave marks. You'll almost always need to sand a little to smooth out the surface.

As you can see, each technology has its moment and its place. The 3D printing market is in full swing, and according to this detailed industry report, spectacular growth is projected over the coming years. This shows that both technologies don't just coexist — they complement each other perfectly!

In the end, many of us do what's inevitable: have one of each type of printer in the workshop! 😉

Safety and maintenance when working with resins

Let's be straight with you: safety comes first when working with resin. Yes, resin 3D printing is amazing, but we can't forget that we're handling chemical products. No need to panic! With a bit of common sense and the right equipment, this is completely safe.

Get comfortable, because I'm going to give you my practical guide, from maker to maker, so you can work with total confidence and without any nasty surprises.

Your maker armor: personal protective equipment

This is non-negotiable — it's your superhero gear for the workshop. Every time you're about to handle liquid resin or freshly printed parts, make sure you're wearing the following:

• Nitrile gloves: Your best friends! They prevent resin from touching your skin, which over time can cause irritation or allergies. Don't take the risk.

• Safety goggles: Your eyes are for admiring the wonderful things you print, not for catching splashes. A small slip-up here can be very costly.

• Mask with carbon filters: Resins release vapors (the infamous VOCs) that you're better off not breathing in. A proper mask filters them out and lets you breathe easy.

• Ventilation, ventilation, and more ventilation: Always print in a well-ventilated room. Opening a window already goes a long way, but if you can place an extractor fan near the 3D printer, you're nailing it.

A myth I want to bust! You don't need a NASA laboratory for this. With your gloves, goggles, mask, and an open window, you have more than enough to work safely at home.

The maintenance that will save you a lot of headaches

Taking care of your 3D printer not only makes it last longer, it will also save you a ton of frustration from failed prints. And I'm telling you this from experience.

• Treat the tank (VAT) like gold: After each print, take a look and check that no small pieces of cured resin are stuck to the FEP film. A single leftover fragment can puncture the film on the next print and cause a real mess.

• The FEP film has an expiry date: That transparent plastic at the bottom of the tank wears out over time. If it looks very scratched or saggy, it's time to replace it. You'll notice an incredible jump in quality!

• Store your resin properly: Bottles should always be kept in a cool, dark place away from sunlight. UV light is their kryptonite. If you have leftover resin in the tank and you're not going to print for a few days, filter it with a strainer and pour it back into the bottle.

Keeping your equipment in top shape is the key to success. If you want to dive deeper into this topic, I recommend checking out my complete guide on basic maintenance for your resin 3D printer, where I walk you through everything step by step. A prepared maker is worth two!

Conclusion: Let's get printing!

Well, maker, we've reached the end of this deep dive into the world of resin. I hope you now have a much clearer picture of what resin 3D printing is and how it works! My goal was to give you a clear map, a guide so you feel confident taking your first steps or refining the technique you already have.

We've covered what's behind the acronyms SLA, DLP, and MSLA, and what the ritual of preparing, printing, washing, and curing a part looks like. Now you know that choosing the right resin is key and that safety comes first. No more excuses!

It's time to get your hands dirty (with gloves on, of course!). I invite you to visit the store, where I've personally selected the resins for 3D printers, printers, and accessories you need to hit the ground running.

And if you feel like sharing your creations, getting questions answered, or simply chatting with other 3D printing enthusiasts like us, come join our community on Telegram: https://t.me/MrResin3D. There we help each other, share coupons, and check out the latest news! And don't forget to subscribe to the newsletter to grab exclusive deals before anyone else.

✨Happy Printing! 🚀

Frequently asked questions about resin 3D printing

Let's get into it. Here I'll put to rest once and for all those questions swirling around in your head before you dive headfirst into the fascinating world of resin. I've got you covered.

Is resin printing very expensive?

You probably think it's a luxury, but you'll be surprised. The cost to get started, with a simple resin 3D printer and a bottle of resin, is more than reasonable. In fact, it's sometimes even more affordable than a mid-range FDM setup. And the best part is that, once you start printing parts — especially small, highly detailed miniatures — the cost per piece is ridiculously low.

Are resin parts fragile?

That's a myth we need to bust right now! The fragility of a part depends one hundred percent on the type of resin you choose. A standard resin can be more delicate, yes, but if you go for an ABS-like resin, you'll be amazed by the strength and durability you can achieve. These are parts built to take a beating. That said, a proper final curing is the secret trick to reaching their maximum hardness.

Does 3D printing resin smell a lot?

I'll be completely honest with you: yes, some resins have their own distinctive chemical "fragrance." The smell varies a lot between brands and types of resin, but the good news is that it's easy to deal with. The golden rule is to always work in a well-ventilated space. With a window open and a mask on, I guarantee the smell will stop being a concern.

Which resin 3D printer would you recommend for beginners?

My advice for your first 3D printer is to look for the perfect balance. Don't go for the cheapest one on the market, but you also don't need an 8K resolution beast to get started. Look for a machine with at least 4K resolution, a print size that suits your projects, and above all, one that has great reviews for being easy to use. With that, you'll have a fantastic setup to start creating truly amazing things.