FDM vs Resin (SLA): What Your Shop Should Offer

Most new print shops start with one technology and add the other once demand shows up. Choosing well saves you thousands in equipment you don't need yet. Here's how FDM and resin actually differ, and what that means for your menu and your prices.

How FDM works, and what it's good at

FDM (fused deposition modeling) melts a plastic filament and lays it down layer by layer. It's the workhorse of the industry for good reason:

• Cheap to run — filament is roughly 20 to 30 dollars per kilogram, and a kilogram goes a long way.
• Big build volumes — most desktop machines print parts up to 220 to 300 mm per side, so you can take larger jobs.
• Tough, functional parts — brackets, enclosures, jigs, fixtures, and replacement parts all play to FDM's strengths.

The trade-off is surface finish. You can see and feel the layer lines, and fine detail below roughly 0.4 mm gets soft.

How resin (SLA/MSLA) works

Resin printers cure liquid photopolymer with UV light, one ultra-thin layer at a time. The result is a different class of detail:

• Crisp detail — miniatures, jewelry masters, dental models, and small mechanical parts come out sharp and smooth.
• Isotropic-ish strength in thin features — great for tiny, intricate geometry that FDM would smear.

The trade-offs are real: resin costs more per liter, build volumes are smaller, prints need washing and UV curing, and uncured resin is messy and requires gloves, ventilation, and careful disposal.

Cost and pricing differences

These print methods don't just cost different amounts — they have a different cost shape, and your quotes should reflect it.

• Material: FDM is priced per gram of filament; resin is priced per milliliter of resin, which usually works out more expensive per finished part.
• Labor: resin carries more hands-on time — draining, washing, curing, and support cleanup — so your labor line should be higher for resin jobs.
• Consumables: resin also eats FEP film, isopropyl alcohol, and gloves. Fold those into your machine or overhead rate so they're not invisible.
• Failure cost: a failed resin print can foul a whole vat; price in a slightly higher spoilage factor.

The cleanest way to keep this straight is a per-material rate rather than one flat number. In KTIZO 3D you can give each material its own density and cost per kilogram (or the resin-equivalent), so an FDM quote and a resin quote come out correct without you doing mental math on every job.

Which should you offer first

If you're choosing one to start: offer FDM. It covers the widest range of functional work, costs less to run, and is far more forgiving while you build your process. Add resin once you're regularly turning away detail-heavy jobs — miniatures, models, dental, jewelry — that FDM can't do well.

Running both

Once you run both, present them as two clear options to customers, each with its own material list and pricing. Let the geometry decide: large or functional goes FDM, small and detailed goes resin. A quoting tool that prices per material and per technology keeps the two from bleeding into each other and protects your margin on both.