FDM vs. Resin 3D Printing: Which One Is Better?

Whether you’re into arts and crafts, want to make prototypes, or start a side hustle, a 3D printer opens up new possibilities. However, finding the right printer can be challenging. Some claim that FDM printers are best for beginners, but are they good enough to produce high-resolution parts? This comparison between FDM vs. resin 3D printing can help you pick the right technology for you.

FDM vs. Resin 3D Printing: Side-by-Side Comparison

For a long time, low-cost 3D printing was synonymous with FDM systems. Resin 3D printing was limited to stereolithography — a technology that came around before FDM, but one that requires sophisticated machines that are ridiculously expensive.

Even today, low-end SLA printers can set you back thousands of dollars. Things changed with the introduction of DLP and LCD printers. These systems use digital light processing or affordable LCD panels to cure the resin in whole layers.

The lower-cost technologies and tech advancements now make it possible to manufacture compact, desktop-sized resin 3D printers suitable for hobbyists. But if you’re an absolute newbie, which system should you get? Briefly, here’s how FDM and resin 3D printing compare.

FDM vs. Resin 3D Printing: What’s the Difference?

Resin 3D printing is the best choice if you want to print high-resolution parts. Items require post-processing, but the results are near-perfect. A wide variety of resin types make it possible to create flexible and rigid items alike.

However, printing with resin is messy and often intimidating for beginners. FDM 3D printing is more approachable. Filaments are easier to work with, and you have a wide range of materials and colors to choose from.

FDM printers are also cheaper than their resin counterparts. However, the print resolution is generally poor, and items may require extensive post-processing to achieve satisfactory results. If you’re not sure which printing technology to start with, this detailed comparison might help you figure it out.

Printing Technologies

The main difference between FDM and resin 3D printing is the technology each system uses to build objects. FDM (fused deposition modeling) printers heat thermoplastic filaments beyond their melting point, then deposit the molten material on a build plate according to a pattern created by a slicer program.

The only similarity with resin 3D printing is that resin printers, too, build objects based on instructions created by a slicer program. The two types of machines may even be able to read the same file extensions, but resin printers use photosensitive resins to build models.

Stereolithography printers are rarely used for hobby or light-duty purposes, but DLP and LCD printers use a similar technique that involves dipping the build surface into a liquid resin vat and curing whole layers at a time to construct the part.

Since the resin is already liquid, there is no thermal process involved. Likewise, FDM filaments aren’t affected by light but by the various temperatures of the nozzle, build plate, and ambient.

Once the molten filament cools and solidifies, the print is ready to use. Post-processing might be required to smooth the surface and increase the part’s aesthetic value, but you can skip it if you want.

Skipping post-processing is not possible if you’re using resin. While the light emitted by the printer cures the resin layer, prints typically need further UV exposure after the print is done. Post-processing with isopropyl alcohol may also be necessary to remove small defects and obtain perfect prints.

Due to the different technologies and amount of post-processing required, FDM printing is typically more straightforward for users, but longer overall. Resin printing is faster, but it is more laborious.

Materials

As mentioned, the different technologies used by each printing system require different materials. All FDM printers use thermoplastic filaments, which come in standard diameters of 1.75mm and 2.85mm. The right diameter should be chosen based on the nozzle diameter that you want to use — the larger the nozzle, the faster the process, but the lower the resolution.

Filament compatibility with different printers makes FDM printing versatile. You can start out with a cheap, entry-level printer and cheap filament to keep costs low until you learn how to design, slice, and calibrate the machine. If you don’t want to compromise on filament quality, you can use high-end filament on a cheap printer — and vice versa if you don’t want to use good filament for prototyping.

Depending on the resin printer, you may be able to use any type of resin, or you may have to buy a specific type. DLP and LCD printers are typically compatible with the same resin types, but some manufacturers require the use of proprietary resin, or the warranty might become void.

SLA resin is also available commercially, but this resin type is not compatible with DLP or LCD printers. Therefore, you should always read the label to avoid buying the wrong resin by mistake.

Color-wise, FDM filaments are typically available in more colors. However, clear resin is much more transparent than clear filaments. There are also more types of specialty resins compared to specialty filaments, including PLA-like and ABS-like resins that have mechanical properties similar to PLA and ABS thermoplastics once cured.

Print Quality

Resin printers win every time when it comes to print quality, provided that you calibrate the machine properly. The secret is the photosensitive resin that can be cured in very thin layers of 0.05mm. Entry-level FDM printers typically have a layer height (thickness) of 0.2mm.

Some printers, such as the Ender 3 Pro and V2, can print thinner layers of 0.1mm, but that’s still thicker than resin. You may think there isn’t much of a difference between these numbers, but the result is a visible transition between the layers in the case of FDM. These lines are very easy to smooth out when printing with resin.

FDM filaments have a lower resolution, but they may require more laborious post-processing, considering that you want to smooth the surface. Some filaments can be smoothed with isopropyl alcohol or acetone vapors, but other filaments don’t respond well to chemical treatments.

In this case, you have to sand the entire surface and polish it with an appropriate product. Depending on how intricate the part is, the process could be straightforward or downright frustrating.

Printing Speed

Another essential difference between FDM and resin 3D printing is the speed — and resin has the upper hand in this department. DLP 3D printers are the fastest, curing up to 700mm of material per hour. Since the printer cures whole layers, it typically takes just over two hours to print a 15cm cube (with any amount of infill from zero or 100 percent).

High-end LCD printers can cure about 350mm of material per hour, lowering the printing speed to about four hours for a 15cm cube. Similar to DLP, LCD printers cure the resin in whole layers, meaning that the infill density doesn’t affect the speed.

SLA is slower than both LCD and DLP, requiring around nine hours to print a 15cm cube. However, FDM printers require up to 90 hours to print the same volume.

The printing speed varies depending on the layer height, infill density, material (different filaments require different extrusion speeds), as well as nozzle and build plate temperature. External factors may also influence print accuracy and, indirectly, print speed.

Thus, if you need a 3D printer for rapid prototyping, you should get a DLP or LCD resin 3D printer. If you couldn’t care less about the time required to complete the project, you could opt for an FDM machine.

Build Volume

If resin printers have print quality and speed, FDM printers win when it comes to the build volume. If you have to build large parts — that don’t necessarily have to have flawless aesthetics — you should get an FDM printer. The less complex technologies standing behind these machines enable manufacturers to develop large FDM printers at affordable prices.

Resin 3D printers are costlier to manufacture. Affordable options are typically desktop-sized. And even then, the build volume can vary widely.

To put things into perspective, a large-volume, freestanding FDM printer can be similarly priced to a small DLP printer from Anycubic. If you want a resin printer with a large build volume, you may have to spend well over $1,000.

Applications

As mentioned, FDM printers are ideal for hobbyists and beginners but also for printing large, functional parts. FDM printing, for instance, is commonly used for ABS and polypropylene prototyping in the aerospace and automotive industries. Research and academic institutes also use FDM printing more than SLA or alternative resin options.

Meanwhile, resin printing is preferred for consumer products, healthcare, and rapid prototyping. Both FDM and resin printing are used in jewelry making, the former for prototyping and the latter for printing finished jewelry and accessories from metal or ceramic-filled resins.

Ease of Use

FDM printers win another point when it comes to ease of use. These printers are straightforward to set up. Once the printer has been installed, all you have to do is load the filament and hit start. After the print is done, you can remove it from the build plate easily (with some exceptions). And, in most cases, you can use the part immediately, as intended.

Post-processing might be necessary to achieve a particular aesthetic or to fully waterproof a container if you didn’t use very precise settings, but it is often unnecessary except for these two purposes.

Print defects can occur, but they are typically the result of improper calibration or the placement of the printer near an open door or window — air currents can affect print quality in FDM printing. However, ambient temperature defects are easy to avoid by using a printer enclosure. Calibration may take some trial and error, but results improve with experience.

Resin printing is a lot messier, as the resin must be used in liquid form. All types of 3D printing resin are toxic and must be handled with care. By contrast, FDM filaments only release toxic fumes when melted, but are otherwise safe to handle.

Hoods must be used to prevent sunlight or other UV light from hitting the resin in the vat, and the printed object is covered in uncured resin when ready. You must wash off the uncured resin with isopropyl alcohol and fully cure the part under a UV light. All these extra steps mean that resin printing has a steeper learning curve and is less ideal for beginners.

Price

Another deciding factor between FDM and resin 3D printers is the price. Both printer types can be found at affordable prices, but resin printers can get expensive fast, depending on the technology they use and the build volume.

For instance, a low-end FDM printer suitable for beginners, such as a simpler Creality model, can cost you under $200. Small-volume LCD printers have a similar price, but when it comes to large build volumes, you can still find suitable FDM options for around $500. Meanwhile, a resin printer with a large build volume can cost you over $2,000.

FDM vs. Resin 3D Printing: 5 Must-Known Facts

1. FDM 3D printers use thermoplastic filaments to build 3D objects. Resin printers use liquid photosensitive resin.
2. Resin printers are ideal for high-accuracy, very detailed printing that needs little post-processing to achieve the desired aesthetics. FDM printers require post-processing to eliminate cosmetic defects.
3. FDM prints are generally ready to use right after printing if you don’t care about aesthetics. Resin prints require post-processing to wash off uncured resin and to properly cure the part.
4. FDM printers are cheaper than resin printers.
5. Liquid resins are toxic; they must be handled with care and stored in secure places. FDM filaments are toxic when melted, but otherwise safe to store and handle.

FDM vs. Resin 3D Printing: Which One Is Better? Which One Should You Use?

If you want a 3D printer to print a bit of everything, you should get an FDM printer. An FDM printer is also right if you’re a beginner. These machines allow you to print a wide variety of models at decent quality, from larger functional parts to miniatures or intricate works of art.

If you want to print small models with impressive details, you should get a resin printer. Specialty resins allow you to print flawless consumer goods, such as phone covers, jewelry, decorative objects, and collectibles. The learning curve may be steeper, but it’s well worth it if you want to turn the hobby into a side gig or craft.