FDM vs Resin vs SLS vs MJF: Which 3D Printing Technology Fits Your Project?

Most people choose a 3D printing technology the wrong way. They start with the process they have heard of and hope the part comes out right. It works better in reverse: decide what the part has to do, then pick the cheapest process that can do it.

This guide compares the four plastic processes 3Ding runs for customers across India: FDM, resin (SLA), SLS, and MJF. You will see how each builds a part, where it is strong, where it falls short, and what it costs to start. Prices, sizes, and materials come from our instant quote page.

The short answer

• FDM is the cheapest and quickest way to get a part in your hands. Use it for prototypes, fit checks, jigs, fixtures, and brackets. You will see layer lines.

• Resin (SLA) gives the smoothest surface and the finest detail. Use it for miniatures, display models, jewellery masters, and clear parts.

• SLS makes tough nylon parts with no support marks. Use it for end-use parts, snap fits, living hinges, and shapes FDM cannot support cleanly.

• MJF makes the same kind of nylon parts as SLS, with a finer, more even finish and consistent results from batch to batch.

If you are unsure, start with FDM. Move to resin only when the surface matters, and to SLS or MJF only when you need real strength or a shape FDM cannot hold.

FDM vs resin vs SLS vs MJF at a glance

*Typical industry figures, not a guarantee. The accuracy of a real part depends on its size, shape, and orientation in the printer.

FDM: the low-cost workhorse

FDM (fused deposition modelling, also called FFF) builds a part by melting plastic filament and laying it down one line at a time, layer on layer. It is the process behind most desktop 3D printers, which is why it is the cheapest and fastest of the four. At 3Ding, small FDM parts are usually ready in 1–2 days, depending on the parts.

The trade-off is the layers. You will see fine ridges on curved and sloped faces, and a part is weakest across its layers, so a bracket loaded the wrong way can split along one. Overhangs need supports, which leave rough patches when removed.

FDM also offers the widest choice of engineering plastics:

• PLA: Cost-effective and stiff. Good for fit checks and display models, but it will not survive heat or direct sun.

• PETG: tougher, and handles heat and chemicals better. Suits enclosures and brackets that have a job to do.

• ABS: handles heat best, which is why it goes into automotive and electrical housings.

• ASA: like ABS, but stands up to sun and weather. The one for outdoor parts.

• TPU: flexible, for seals, grips, and gaskets.

For a deeper look at the three common filaments, read PLA vs ABS vs PETG. Ready to print? See our FDM 3D printing service.

Resin (SLA): fine detail and smooth surfaces

Resin 3D printing, usually called SLA (stereolithography), builds a part from liquid photopolymer that hardens wherever UV light hits it. Light can be controlled far more finely than a nozzle, so layers are thinner, edges are sharper, and small text and textures come out clean.

That detail comes with limits. Standard resin is brittle: it can crack under a sharp knock or when a snap fit flexes. The largest resin part we print is 200 mm on each side, supports leave small marks that need light sanding, and most resins are not made for long outdoor use. The minimum is also higher, at Rs. 1,000 + GST per file.

Pick the resin by the job:

• Standard (white or black): display models, miniatures, and detailed samples.

• ABS-like (white, black, or grey): tougher and less brittle than Standard, for prototypes that get handled.

• Standard Clear: for parts you need to see through.

• Flexible 65D (black): for parts that need to give a little.

More in our FDM vs resin guide, or order through our resin 3D printing service.

SLS: tough nylon without supports

SLS (selective laser sintering) spreads a thin layer of nylon powder, and a laser fuses the cross-section of each part. The loose powder around the part holds it up, so there are no supports to remove, and parts can be packed closely through the whole build.

The result is nylon PA12 that is tough, slightly flexible, and strong in every direction. That makes SLS the right call for end-use parts, snap fits, living hinges, internal channels, and shapes that would need heavy supports on FDM. Parts come out white with a matte, slightly grainy surface.

The costs are a higher starting price, Rs. 2,000 + GST per file, and some design care: a hollow part needs escape holes so trapped powder can be cleaned out. More on the process in the advantages of SLS, or go straight to our SLS 3D printing service.

MJF: nylon parts with a finer finish

MJF (Multi Jet Fusion), developed by HP, also starts with a bed of nylon powder. Instead of a laser tracing each part, an inkjet head prints a fusing agent where the part should be and a detailing agent along its edges. Infrared heat then fuses the whole layer in one pass.

Because the powder is finer and each layer is fused at once, MJF gives a smoother, more even matte surface, crisp small features, and consistent results across a batch. Our MJF parts come out grey and can be as large as 380 × 280 × 380 mm, the biggest nylon option we offer. The minimum is the same as SLS, and hollow parts still need escape holes. Read our MJF guide or see the MJF 3D printing service.

SLS or MJF? The closest call

These two compete for the same jobs, and for most functional parts either will work. Published comparisons disagree on which is stronger, and the gap is small. Decide on the practical differences:

• Finish and detail: MJF surfaces are a little smoother, and small text comes out crisper.

• Colour: our SLS parts are white; our MJF parts are grey.

• Size: MJF takes parts up to 380 mm in X and Z; SLS up to 300 mm each way.

• Repeat orders: if the same part will be reordered in batches, MJF's consistency helps.

If your part fits both, get it priced in both and decide on price and colour.

Pick by what the part has to do

What changes the price

• Minimum per file. Every file carries a minimum charge (see the table above). It covers file prep, printer setup, cleaning, and packing.

• Size and height. Bigger and taller parts use more material and machine time.

• Quality and infill on FDM. You choose the quality setting (draft, standard, or high) and the infill density. Lower infill is lighter and cheaper; higher is stronger.

• Quantity. On FDM, Rs. 200 covers one or two pieces, then each extra piece costs at least Rs. 100 (before GST).

• Delivery. Shipping is Rs. 200 (GST included) on print orders under Rs. 1,500 and free above that. Pickup in Chennai is free.

Support removal and basic cleanup are always included. Spray painting and threaded inserts cost extra, subject to availability.

Common mistakes to avoid

• Ordering standard resin for a part that takes knocks or flexes. Use ABS-like resin or nylon.

• Printing a load-bearing FDM part with the layers running across the load.

• Jumping to SLS or MJF for a first fit check. Prove the shape in PLA, then move up.

• Designing a hollow nylon part with no escape holes for the powder.

• Modelling mating parts with zero clearance. A common guideline for SLS and MJF is about 0.4 mm between parts that must fit together.

Frequently asked questions

Which 3D printing technology makes the strongest parts?

SLS and MJF. Their nylon PA12 parts are tough and similar in strength in every direction. FDM parts in PETG or ABS can be strong along the layers but weaker across them. Standard resin is the most brittle of the four.

Is resin printing better than FDM?

For detail and surface finish, yes. For strength, size, and cost, FDM usually wins. At 3Ding, resin starts at Rs. 1,000 + GST per file and FDM at Rs. 200 + GST.

Which is the cheapest way to print one part?

FDM 3D printing is generally one of the most affordable options for simple parts and prototypes. At 3Ding, 3D printing starts at a minimum charge of ₹200 + GST, making it a cost-effective choice for small projects.

Is MJF better than SLS?

Not in general. MJF gives a finer, more even finish and consistent batches; SLS gives white parts. Strength is similar, so choose on finish, colour, size, and price.

Which technology is the most accurate?

Resin usually holds the tightest tolerances on small parts (about ±0.15 mm), followed by SLS and MJF (about ±0.3%), and then FDM (about ±0.5 mm).

Can you print a part bigger than the build size?

Yes. We split it into sections and join them after printing. Upload the file, click Request Review, and we will quote it.

What files can I upload?

STL, OBJ, STEP, or STP, up to 100 MB per file. If you only have a sketch or a physical part, our 3D design and 3D scanning services can create the file.

Still not sure? Upload the file

Upload your STL, OBJ, or STEP file on our instant quote page. You will see the price and production time before you pay, and you can add your GSTIN at checkout for a GST invoice. Your files are used only to make your parts and are never shared or sold. If the part is large or unusual, or you want a second opinion, click Request Review and our team will take a look.