3D Printing Technology: FDM VS. SLA VS. SLS


Additive manufacturing or 3D printing can help you lower production costs, cut the leads time of production, and increase the efficiency processes for product development. Moreover, the concept models and functional prototypes in rapid prototyping for making jigs & fixtures, or even end-use parts in manufacturing. 3D printing technologies offer versatile solutions in a wide variety of applications.

In additional, over the last few years high-resolution 3D printers have become more affordable and easier to use with more reliable functions. The technology is now accessible to more businesses but choosing between the various competing 3D printing solutions can be difficult.

In this article, we’ll identify at the three most established technologies for 3D printing plastics that are FDM, SLA, and SLS.


First technology is Fused Deposition Modeling is the most widely used form of 3D printing at the consumer level, fueled by the emergence of hobbyist 3D printers. FDM 3D printers build parts by melting and extruding thermoplastic filament, which a print nozzle deposits layer by layer in the build area or print plate.

It works with a range of standard thermoplastics such as ABS, PLA, and their various blends. The technique is well-suited for basic proof-of-concept models, as well as quick and low-cost prototyping of simple parts. For example,  parts that might typically be machined.

*Credit Images: Markforged
This technology have visible layer lines and might show inaccuracies around complex design. 

It has the lowest resolution and accuracy when compared to SLA or SLS and it is not the best option for printing complex designs or parts with intricate features. Higher-quality finishes may be obtained through chemical and mechanical polishing processes. Industrial FDM 3D printers use soluble supports to get rid some of these issues and offer a wider range of engineering thermoplastics but it might have higher in price.


It was the world’s first 3D printing technology, invented in the 1980s, and is still one of the most popular technologies for professionals. SLA uses a laser to cure liquid resin into hardened plastic in a process called photopolymerization.

SLA parts have the highest resolution and accuracy, clearest details, and the smoothest surface finish of all plastic 3D printing technologies. The main benefit of SLA lies in its versatility. Material manufacturers have created innovative SLA resin formulations with a wide range of optical, mechanical, and thermal properties to match those engineering, and industrial thermoplastics ‘s standard.

*Credit Images: Markforged
Surface’s parts have sharp edges, a smooth surface finish, and minimal visible layer lines. 

Besides, it is a great option for highly detailed prototypes requiring strong and smooth surfaces, such as molds, patterns, and functional parts. SLA is widely used in a range of industries from engineering and product design to manufacturing, dentistry, jewelry, model making, and education.


Selective laser sintering is the most common additive manufacturing technology for industrial applications. 3D printers use a high-powered laser to fuse small particles of polymer powder. The unfused powder supports the part during printing and eliminates the need for dedicated support structures. This makes SLS ideal for complex geometries, including interior features, undercuts, thin walls, and negative features. Parts produced with SLS printing have excellent mechanical characteristics, with strength resembling that of injection-molded parts.







*Credit Images: Markforged

Slightly rough surface finish, but almost no visible layer lines. This example part was printed on a Formlabs Fuse 1 benchtop SLS 3D printer.

The most common material for selective laser sintering is nylon, a popular engineering thermoplastic with excellent mechanical properties. Nylon is lightweight, strong, and flexible, as well as stable against impact, chemicals, heat, UV light, water, and dirt.

The combination of low cost per part, high productivity, and established materials make SLS a popular choice among engineers for functional prototyping, and a cost-effective alternative to injection molding for limited-run or bridge manufacturing.


However, each 3D printing technology has its own strengths, weaknesses, and requirements. It is suitable for different applications and businesses. The following table summarizes some key characteristics and considerations.

  Fused Deposition Modeling (FDM) Stereolithography (SLA) Selective Laser Sintering (SLS)
Resolution ★★☆☆☆ ★★★★★ ★★★★☆
Accuracy ★★★★☆ ★★★★★ ★★★★★
Surface Finish ★★☆☆☆ ★★★★★ ★★★★☆
Throughput ★★★★☆ ★★★★☆ ★★★★★
Complex Designs ★★★☆☆ ★★★★☆ ★★★★★
Ease of Use ★★★★★ ★★★★★ ★★★★☆
Pros Fast
Low-cost consumer machines and materials
Great value
High accuracy
Smooth surface finish
Range of functional applications
Strong functional parts
Design freedom
No need for support structures
Cons Low accuracy
Low details
Limited design compatibility
Average build volume
Sensitive to long exposure to UV light
Rough surface finish
Limited material options
Applications Low-cost rapid prototyping
Basic proof-of-concept models
Functional prototyping
Dental applications
Jewelry prototyping and casting
Functional prototyping
Short-run, bridge, or custom manufacturing
Print Volume Up to ~200 x 200 x 300 mm (desktop 3D printers) Up to 145 x 145 x 175 mm (desktop 3D printers) Up to 165 x 165 x 320 mm (benchtop 3D printers)
Materials Standard thermoplastics, such as ABS, PLA, and their various blends. Varieties of resin (thermosetting plastics). Standard, engineering (ABS-like, PP-like, flexible, heat-resistant), castable, dental, and medical (biocompatible). Engineering thermoplastics. Nylon 11, Nylon 12, and their composites.
Training Minor training on build setup, machine operation, and finishing; moderate training on maintenance. Plug and play. Minor training on build setup, maintenance, machine operation, and finishing. Moderate training on build setup, maintenance, machine operation, and finishing.
Facility Requirements Air-conditioned environment or preferably custom ventilation for desktop machines. Desktop machines are suitable for an office environment. Workshop environment with moderate space requirements for benchtop systems.
Ancillary Equipment Support removal system for machines with soluble supports (optionally automated), finishing tools. Post-curing station, washing station (optionally automated), finishing tools. Post-processing station for part cleaning and material recovery.


Costs controlling  does not end with upfront equipment costs. Material and labor costs have a significant influence on cost per part, depending on the application and your production needs.

Below is the detailed breakdown by technology:

  Fused Deposition Modeling (FDM) Stereolithography (SLA) Selective Laser Sintering (SLS)
Equipment Costs Mid-range desktop printers start at $2,000, and industrial systems are available from $15,000. Professional desktop printers start at $3,500, and large-scale industrial machines are available from $80,000. Benchtop systems start at $10,000, and industrial printers are available from $100,000.
Material Costs $50-$150/kg for most standard and engineering filaments, and $100-200/kg for support materials. $149-$200/L for most standard and engineering resins. $100/kg for nylon. SLS requires no support structures, and unfused powder can be reused, which lowers material costs.
Labor Needs Manual support removal (can be mostly automated for industrial systems with soluble supports). Lengthy post-processing is required for a high-quality finish. Washing and post-curing (both can be mostly automated). Simple post-processing to remove support marks. Simple cleaning to remove excess powder.