The FDM-vs-resin decision is the single most consequential choice in 3D printing, and it's about more than print quality — one of these technologies involves genuine chemical safety considerations the other doesn't have at all.
FDM: melted plastic filament, no chemical handling
FDM (Fused Deposition Modeling) printers melt and extrude solid plastic filament layer by layer, the way most people picture 3D printing working. There's no liquid chemical handling involved — filament is a solid spool, and the process doesn't produce anything requiring special PPE beyond basic care around a hot nozzle. FDM printers are generally more affordable, easier to maintain, and better suited to functional parts and larger prints, at the cost of visible layer lines and generally less fine surface detail than resin printing produces.
Resin: exceptional detail, but with real, ongoing safety requirements
Resin (SLA/MSLA) printers cure liquid photopolymer resin with UV light, producing significantly finer detail and smoother surfaces than FDM — the clear choice for miniatures, jewelry patterns, or anything needing fine detail. But this comes with a genuine chemical handling requirement that isn't optional or a minor inconvenience: uncured liquid resin is a real skin and respiratory irritant, and repeated exposure can cause sensitization — an allergic-type immune response that can develop suddenly after months of previously uneventful handling, turning into a lasting reaction. This means resin printing requires actual PPE (nitrile gloves rated at least 5 mil thick — thinner food-prep gloves aren't sufficient, and latex gloves let resin through faster than nitrile) and real ventilation to outside air, not just a well-lit garage or spare room.
An important, easy-to-miss detail: the off-gassing doesn't stop when the print finishes. Uncured resin remaining on a freshly printed part continues releasing fumes until it's been fully post-cured, meaning the safety considerations extend beyond just the printing process itself into handling and post-processing.
If choosing resin, treat it like a real workspace requirement, not an accessory
Given the above, resin printing isn't well suited to a bedroom, living room, or any space without real ventilation to the outside — most safety guidance treats a resin printing area more like a small chemical workspace than a hobby corner, with dedicated ventilation, no food or drink nearby, and consistent glove use for anything that's touched uncured resin, including tools and surfaces. This is a genuine, ongoing space and habit requirement, not a one-time setup cost.
Build volume and print speed are simpler, more familiar tradeoffs
Beyond the FDM-vs-resin decision, larger build volumes allow bigger single prints but generally cost more; faster print speeds save time but can reduce quality at the top end of a printer's speed range. These tradeoffs work similarly to other tool categories — matching the spec to actual intended project sizes and patience for print time, rather than assuming maximum build volume or speed is automatically the right choice.
The one thing people forget
For a resin printer specifically, plan for isopropyl alcohol (or a dedicated wash solution) and a curing station as real, ongoing supply costs beyond the resin and printer themselves — the full post-processing workflow (wash, cure) is a required part of resin printing, not an optional extra step, and budgeting for these consumables and equipment upfront avoids an incomplete setup that can't safely or properly finish a print.