Resin Exists, We're Not Doing It, Here's Why
Every couple classes somebody asks me about resin printers. Usually because they saw one online making a miniature with details so fine it looks carved instead of printed. Fair question. I want to answer it straight instead of waving it off.
Short version: resin is a real technology, it makes genuinely better-looking small detailed parts than FDM, and I have never owned one and I'm not going to teach it in this class.
Let me actually explain why, because "I've never done it" isn't the whole reason.
What resin printing actually is
FDM, what we've been talking about the last three lessons, works by melting plastic filament and stacking it layer by layer. Resin printing is a completely different process. Instead of melted plastic, you've got a vat of liquid photopolymer resin, and the printer uses a UV light source underneath (or above, depending on the machine) to cure that liquid into a solid shape, one thin layer at a time. The build plate lifts, a new layer of liquid resin gets exposed, it cures, repeat.
That's why resin prints can get so much finer detail. The light can cure a much smaller point than a nozzle can extrude plastic through. If you want a tiny miniature with facial details or fine jewelry-scale work, resin is genuinely the better tool. I'm not going to pretend otherwise.
Why I don't teach it
Three reasons, and they're not equal.
One, different machine, different everything. The mechanics, the software, the failure modes, the maintenance — none of it transfers from what we're learning. Teaching resin would basically be a second class, not an add-on lesson.
Two, the mess is a real mess. Liquid resin gets everywhere it touches until it's cured, and it does not want to come off your hands, your table, or your clothes. You need isopropyl alcohol on hand for cleanup, every time, no exceptions.
Three, and this is the one that actually matters — the chemicals are not casual. Uncured resin is a skin irritant for a lot of people and it's genuinely toxic if you're not careful with it. You need gloves. You need ventilation, real ventilation, not just a cracked window. Some people develop sensitivity to it over repeated exposure even if the first few times didn't bother them. And the isopropyl alcohol you use for cleanup and the leftover resin waste both need to be handled and disposed of properly, not dumped down a drain.
That's a whole separate safety conversation, with its own equipment, in a room set up for it. I don't have that setup here, and honestly, I haven't lived with it myself. I don't teach what I haven't done. If I stood up here and gave you resin safety advice off a forum I read once, that'd be worse than not teaching it at all.
So: PLA, FDM, filament. That's this whole class. If resin still interests you after this, there are dedicated resin classes out there and you should take one from somebody who actually runs that equipment daily.
What FDM is genuinely good at instead
I don't want this lesson to be all "here's what we're not doing." FDM earns its keep in a different lane. It's cheap to run, it's forgiving of a beginner's mistakes, the material is stable and low-fume, and it's excellent for functional parts — brackets, mounts, organizers, anything that needs to hold up under actual use rather than look pretty on a shelf.
Case in point: my daughter Madison used to lose her retainer about once a week. Drove everyone in the house a little crazy. I printed a small wall mount for it, labeled it, stuck it by her bathroom sink. Nothing fancy, no fine detail work, just a functional bracket that holds a shape. Retainer's been lost exactly zero times since I put it up. That's the kind of win FDM is built for. Nobody needs sculpted detail on a retainer mount. They need it to exist, work, and cost me about 20 cents in filament.
That's my opinion and I'll stand behind it: PLA covers almost everything a beginner actually needs. People get tempted to chase fancier materials or fancier processes to feel like they're advancing. Get comfortable here first. Print a hundred things in plain PLA before you go looking for a reason to branch out. If resin still calls to you after that, at least you'll know what you actually need it for instead of just wanting the fancier machine.
Before next time
No print assignment this round. Just think about one thing in your house that's actually broken, missing a piece, or annoying you the way that junk drawer annoyed me two winters ago. That's going to be useful once we get into design and slicing.