Choosing the right 3D printing process is the first — and most important — decision in any prototyping or production project.

Each process has strengths, trade-offs, and ideal use cases. At PartSnap, we work with six processes — three in-house and three through our production network — and help clients choose the right one every day. Here’s what we’ve learned from over a decade of printing.

Quick Comparison

Feature FDM SLA FFF MJF SLS Metal (DMLS)
Best For Functional parts Fine detail, cosmetic Early concepts Best of both worlds Complex geometry Extreme applications
Material ABS, ULTEM, PC Resin PLA, PETG Nylon (PA 12/11) Nylon (PA 12/11) Ti, Steel, Inconel
Strength Excellent Moderate Moderate Excellent Excellent Superior
Surface Finish Good Excellent Acceptable Very Good Good (matte) Rough (needs finishing)
Porosity Some (layer gaps) Zero Some Zero Near-zero Zero (fully dense)
Support Structures Required Required Required None (powder bed) None (powder bed) Required
In-House ✅ PartSnap ✅ PartSnap ✅ PartSnap Partner network Partner network Partner network
Relative Cost $$$ $$ $ $$$ $$$ $$$$$

In-House Processes

FDM — Fused Deposition Modeling

Our Stratasys Fortus system — professional-grade, not desktop

FDM is the workhorse of professional 3D printing. It builds parts from real engineering thermoplastics — ABS, polycarbonate, and ULTEM — by extruding material layer by layer.

Choose FDM when you need:

  • Functional prototypes that will be handled, tested, and abused
  • Production-grade materials with specific mechanical, thermal, or chemical properties
  • End-use parts or manufacturing fixtures for daily use
  • Large parts (build volume: 16″ × 14″ × 16″)
  • ULTEM 9085 for aerospace applications requiring FST certification

Learn more about FDM →

SLA — Stereolithography

Our Formlabs Form 3 — precision resin printing

SLA uses a laser to cure liquid resin, producing parts with the finest surface finish and highest detail resolution of any process we run.

Choose SLA when you need:

  • Presentation-quality prototypes for clients or investors
  • Fine details — thin walls, small text, snap features, textures
  • Clear or transparent parts
  • Patterns for urethane casting
  • Form and fit testing before committing to injection mold tooling

Learn more about SLA →

FFF — Fused Filament Fabrication

Consumer-grade printing for fast, low-cost concepts

FFF uses open-source PLA filament for quick visual prototypes. Not suitable for functional testing, but perfect for early-stage iteration.

Choose FFF when you need:

  • Quick visual models to communicate a concept
  • Color prototypes for presentations
  • Budget-conscious early-stage iteration

Partner Network Processes

We source these processes through qualified production partners — same engineering oversight, single point of contact.

HP Multi Jet Fusion (MJF)

Real nylon. Zero porosity. The best of both worlds.

MJF builds parts from thermoplastic nylon powder using chemical sintering. The result combines the strength of FDM with the surface quality of SLA — and delivers fully dense, airtight, watertight parts.

Choose MJF when you need:

  • Watertight or airtight nylon parts (zero porosity)
  • Complex internal geometry (no support structures needed)
  • Isotropic strength (equal in all directions — unlike FDM’s layer weakness)
  • Small to mid-volume production (50–500+ parts)
  • Functional snap fits, living hinges, or mechanical features in nylon

Learn more about MJF →

SLS — Selective Laser Sintering

Maximum geometric freedom in engineering nylon

SLS uses a laser to fuse nylon powder, producing parts with excellent mechanical properties and no support structures. Wider material range than MJF, including flame-retardant and glass-filled variants.

Choose SLS when you need:

  • Complex assemblies printed as one piece (hinges, interlocking parts)
  • Flame-retardant or specialty nylon variants
  • Batch production of functional nylon parts
  • Parts where every surface is a “show surface” (no support marks)

Learn more about SLS →

Metal 3D Printing (DMLS/SLM)

Fully dense metal parts — titanium, Inconel, stainless, aluminum

Metal AM builds real metal parts by laser-melting metal powder. Mechanical properties match or exceed wrought metal. Used when geometry can’t be machined, material is exotic, or weight reduction is critical.

Choose metal AM when you need:

  • Geometry that can’t be CNC machined (internal channels, topology-optimized shapes)
  • Titanium, Inconel, or cobalt chrome parts
  • Weight reduction through topology optimization
  • Conformal cooling channels in injection mold tooling
  • Low quantities of complex metal parts without tooling investment

Learn more about Metal 3D Printing →

Decision Flowchart

Start here: What matters most for your part?

  • “It needs to survive real-world use” → FDM (ABS, ULTEM) or MJF (nylon)
  • “It needs to look production-ready” → SLA or PolyJet
  • “It needs to be watertight/airtight” → MJF
  • “It has complex internal geometry” → SLS or MJF (no supports needed)
  • “It needs multiple materials in one part” → PolyJet
  • “It needs to be metal” → DMLS/SLM
  • “I just need to see the concept in 3D” → FFF
  • “I’m not sure yet” → Talk to us — we’ll help you decide

Still not sure? That’s what we’re here for.

Choosing a 3D printing process involves trade-offs between cost, speed, material properties, and surface finish. We help clients navigate these decisions every day — and we’ll give you an honest recommendation even if it means a less expensive option or a process we don’t run in-house.

Request a Quote →

info@partsnap.com · 214.449.1455