FDM vs SLA vs SLS vs MJF vs Metal: Which 3D Printing Process?

There are five 3D printing processes you are likely to come across in Singapore: FDM, SLA, SLS, MJF and metal printing. Each is the right answer for some parts and the wrong answer for others. The quickest way to choose is to start from what the part has to do, then pick the process that does it at a sensible cost.

We are an FDM specialist. We only run FDM in-house, so this guide is also our honest view of when FDM is the wrong answer. When it is, we tell you which process fits and what to ask a provider for, rather than printing something that will disappoint you.

The Short Answer: A Decision Table

Find the row that best matches your part. If two rows apply, the stricter requirement usually wins.

If your part needs…	Usually choose	Why
Toughness, heat or UV resistance at low cost	FDM	Engineering filaments (PETG, ASA, nylon, carbon-fibre grades) at a low price per part
Large size, up to roughly a shoebox in one piece	FDM	Large build volumes are common and affordable
Jigs, fixtures, brackets, enclosures	FDM	Strong, quick, cheap to revise
Very fine detail and a smooth surface on a small part	SLA (resin)	Thin layers and no visible extrusion lines
Complex nylon parts with no support marks, internal channels or interlocking pieces	SLS	The powder bed supports the part, so almost any geometry prints
Dozens to hundreds of small nylon parts with consistent properties	MJF	Fast powder-bed process with even strength in all directions
Metal strength, high heat beyond plastics, or a metal-only spec	Metal (LPBF or binder jetting)	Real metal parts, at a much higher price

FDM: Tough, Large and Affordable

FDM melts plastic filament and lays it down layer by layer. It is the best fit for most functional parts: brackets, housings, jigs and fixtures, replacement parts and prototypes. Material choice is wide, from PETG for everyday parts to carbon-fibre grades like PA-CF for stiff, hot jobs.

FDM has real limits, and it helps to know them:

• Accuracy: typical tolerances are ±0.2–0.5 mm. Holes come out 0.1–0.2 mm undersize.
• Surface: layer lines are always visible to some degree.
• Detail: walls under 0.4 mm won't print at all, and tiny features soften.
• Direction: parts are weaker between layers than along them.

If those limits are fine for your part, FDM is almost always the cheapest and fastest route. Our guide on how strong 3D-printed parts are covers the strength side in more detail.

SLA: Detail and Smooth Surfaces

SLA, or resin printing, cures liquid resin with light. It wins on fine detail and surface finish, which makes it the right choice for small display figures, jewellery masters, dental-style models and tiny parts with crisp text. Standard resins are more brittle than FDM plastics, and parts can degrade in sunlight. We compare the two in depth in FDM vs resin 3D printing, so we won't repeat it here.

What to ask an SLA provider

• Which resin they recommend for your use: standard, tough, flexible, high-temperature or castable
• The layer height and the expected accuracy for your part size
• Where support marks will land, and whether they will be sanded off
• Whether parts are fully washed and post-cured before handover

SLS: Complex Nylon Parts Without Supports

SLS (selective laser sintering) uses a laser to fuse nylon powder. The unfused powder supports the part as it prints, so overhangs, internal channels and interlocking pieces print without support structures. Parts come out tough, slightly grainy and usually white or grey. SLS is a good fit for snap-fit housings, ducting, complex brackets and functional prototypes where FDM's layer direction or supports would be a problem.

What to ask an SLS provider

• Which nylon grade they run (PA12 and PA11 are common) and its properties
• Minimum wall thickness and the size of escape holes needed to clear powder from hollow parts
• Surface finish options: bead blasting, dyeing, smoothing
• How pricing works: many providers charge by part volume or bounding box rather than by weight

MJF: Consistent Nylon Parts in Volume

MJF (Multi Jet Fusion) is also a powder-bed nylon process. Instead of a laser, it uses fusing agents and heat across the whole layer, which makes it fast for full builds. Parts have fairly even strength in every direction and a fine, slightly grainy grey finish, often dyed black. MJF suits batches of small to medium nylon parts that must all behave the same.

What to ask an MJF provider

• Which materials are available (PA12 is standard; PA11 and TPU are offered by some)
• Whether dyeing or vapour smoothing is included or extra
• Price breaks for quantity, since parts are nested together in a build
• Lead time for a full build versus a single part

Metal Printing: When It Has to Be Metal

Metal printing covers processes like laser powder bed fusion (LPBF) and binder jetting. It produces real stainless steel, aluminium, titanium and other alloy parts. It is the right call when the part must be metal for strength, heat, conductivity or certification reasons. It is also far more expensive than plastic printing and often needs machining afterwards.

Before going to metal, it is worth asking whether a stiff, heat-resistant plastic would do. Our PPA-CF keeps its strength past 200 °C and resists oils and fuels, which makes it a candidate to replace some machined metal brackets and fixtures.

What to ask a metal printing provider

• Which alloy, and which process (LPBF or binder jetting), suits your part
• Which surfaces will be machined after printing, and to what tolerance
• Whether heat treatment or stress relief is included
• How supports are removed and what surface they leave behind
• What inspection or material documentation they can provide

When We Tell You FDM Is the Wrong Answer

Every file we receive gets a free check before it goes on a printer. Sometimes that check shows FDM is not the right process. Common reasons:

• Detail finer than FDM can resolve, such as tiny text or very thin features
• Tolerances tighter than ±0.2 mm across the whole part
• Internal channels that cannot be supported or cleared
• A part that must be metal, or certified for a regulated use

When that happens, we say so plainly. We tell you which process fits, and give you the questions above to ask a provider. We won't take your money for a print that will fail. Sometimes a small design change brings a part back within FDM's limits, and we'll suggest that too. Read more in why we sometimes say no to a print.

Quick FAQ

Which process is cheapest?

For most plastic parts, FDM. SLA can be cheap for very small parts, and MJF becomes competitive for many small nylon parts in one build. Metal is the most expensive by a wide margin.

Do you offer SLA, SLS, MJF or metal?

No. We only run FDM in-house. If your part needs another process, we'll tell you which one and what to ask for.

Is FDM strong enough for end-use parts?

Often, yes. Brackets, enclosures, jigs and replacement parts in PETG, ASA, nylon or carbon-fibre grades are used as end-use parts every day.

How do I know which process my part needs?

Upload it to our quote page. You get an instant FDM price, and our free file check will flag it if another process would serve you better.

Not sure FDM is right for your part? Upload it and we'll tell you honestly. Get an instant quote.