The most expensive myth in 3D printing goes like this: "the more infill, the stronger the print". The truth is the opposite — 4 wall perimeters at 30 % infill give you a stiffer part than 2 perimeters at 100 % infill, and they print far faster while using less material. It is one of ten myths that have taken root in the 3D printing community over the years and still cost people time, filament and nerves. If you are just choosing your first material, start with PLA filaments — but first check how much of what "everybody knows" actually holds up.
We collected ten claims we hear most often — in groups, at trade shows and in conversations with customers. For each one we show where it came from (because most myths have a real origin), where it stopped being true and what to do instead. No theory for the sake of theory: every point ends with a concrete setting or a decision you can make today.
10 3D printing myths — quick reference table
| Myth | How it really works | What follows from it |
|---|---|---|
| 100 % infill = strongest print | Strength is driven mainly by walls and part orientation | Increase perimeters, not infill |
| PLA will decompose in the garden compost bin | PLA requires industrial composting conditions (approx. 58 °C, controlled humidity) | Treat prints as plastic, not as organic waste |
| Thinner layers always mean better | 0.1 mm improves looks but doubles print time and adds no strength | 0.2 mm as default, 0.1 mm only for detail |
| PLA is only good for toys | PLA is very stiff; its limit is temperature, not strength | Indoors PLA is enough, for heat choose PETG/ASA |
| Expensive filament always prints better | Diameter tolerance and batch consistency matter, not the price tag | Compare technical data, not labels |
| Drying filament is overkill | PETG, TPU and nylon absorb moisture within days, not months | A dry box is cheaper than one failed print |
| Higher temperature always ruins the print | Too low a nozzle temperature causes delamination more often than too high | Run a temperature tower for every spool |
| A cheap printer cannot produce good prints | Calibration and material make the biggest difference, not machine price | Calibrate flow and e-steps before changing hardware |
| 3D printing is slow | Input shaping and higher flow have cut typical print times many times over | Update firmware and profile before blaming the machine |
| You need CAD skills to print | Model libraries cover most household use cases | CAD matters only once you design your own parts |
We collected concrete temperature values for every material in one place — see the print temperature table if you are looking for a starting point for a new spool.
Why 3D printing myths are so persistent
Most of them used to be true. Ten years ago printers really were slow, filaments had poor diameter tolerance and default slicer profiles were built by trial and error. Someone wrote down a conclusion — correct under those conditions — and the conclusion started living a life of its own, long after hardware and materials had moved on.
The second reason is more human: in 3D printing it is very hard to separate cause from coincidence. You change three things at once, the print comes out better and you credit the change that felt most important. That is how "proven" settings are born that nobody ever verified in isolation. You can see it clearly in the eternal material debate — we took it apart in PLA or ABS.
The third reason is forums and videos. The advice "set infill to 100 %" is short, sounds reasonable and needs no explanation. The advice "raise perimeters to four, because in bending it is mainly the outer material that works" needs two more sentences — and loses the race for attention. Myths win because they are simpler, not because they are true.
Material myths
Myth 1: PLA is only good for toys
PLA is one of the stiffest widely available filaments — under static load it outperforms ABS. Its real limitation is a glass transition temperature around 60 °C: a part left in a car in summer will deform, though indoors it will last for years. For brackets, enclosures, organisers and interior parts PLA is a rational choice, not a compromise. Only when heat, sunlight or outdoor use come into play do you reach for PETG, ASA or nylon.
Myth 2: PLA will decompose in the compost bin behind the house
This is the most repeated environmental myth in the whole industry. PLA is made from renewable feedstock and is industrially compostable, but decomposition requires conditions a garden compost bin does not have: temperatures around 58 °C sustained for weeks, the right humidity and microflora. In a garden, in water or in landfill a PLA print will not disappear within any reasonable time — it behaves like ordinary plastic. So the honest message is: PLA has a better feedstock footprint, but you throw the print into plastics, not into organic waste.
Myth 3: more expensive filament always prints better
Price is a very weak predictor of quality. What actually affects the print can be listed: diameter tolerance, batch-to-batch consistency, granulate purity, spool winding and moisture content at packing time. Filament with good diameter tolerance prints predictably, because flow does not drift during the job. Carelessly wound filament can jam the feeder halfway through an eight-hour print — regardless of what it cost. Instead of comparing prices, compare technical data sheets and look for manufacturers who publish them at all.
Settings myths
Myth 4: 100 % infill gives the strongest part
In bending — the way most functional prints actually break — it is mainly the material at the outside of the cross-section that works. That is why raising perimeters from 2 to 4 (with a 0.4 mm nozzle that means a wall growing from 0.8 mm to 1.6 mm) does noticeably more than raising infill from 30 % to 100 %. Full infill has one more downside: it accumulates shrinkage stress and on larger parts encourages lifting from the bed. A sensible default set is 4 perimeters, 5 top/bottom layers and 25–35 % gyroid or grid infill.
Myth 5: a thinner layer means a better print
A 0.1 mm layer height improves the look of sloped surfaces and fine detail — and that is where the benefits end. Print time roughly doubles compared to 0.2 mm, while strength does not increase; with very thin layers interlayer adhesion can even drop, because each layer receives less thermal energy. For functional parts 0.2 mm is the default choice, 0.3 mm works great on large solids, and 0.1 mm should be reserved for figurines and parts someone will look at up close.
Myth 6: higher temperature always ruins the print
Beginners instinctively lower the temperature when they see stringing or blobs. Yet the most common cause of prints cracking along layer lines is a temperature that is too low, not too high — hotter material bonds better to the layer below. Too high a nozzle temperature shows up differently: stringing, scorched detail, material building up on the nozzle and worse bridging. Instead of guessing, print a temperature tower for every new spool; it takes about fifteen minutes and settles the question for good.
Hardware and process myths
Myth 7: you cannot get good prints from a cheap printer
The biggest quality differences come from calibration, not from the price of the machine. Correctly set extruder e-steps, calibrated flow, a level bed and a sensible first layer produce a quality jump you cannot buy with a more expensive printer running a default profile. Yes, a stiffer frame and input shaping let you print faster at the same quality — but that is a gain in time, not in print geometry itself. Before you decide you need new hardware, run a full calibration of what you already have.
Myth 8: drying filament is something only professionals need
PETG, TPU and nylon are hygroscopic and absorb moisture from the air within days, not months. The symptoms are characteristic: popping and hissing at the nozzle, a matte or rough surface, bubbles, worse layer adhesion and a sudden rise in stringing on a spool that printed flawlessly before. Nylon can lose its properties after a single night in a humid room. A cheap dry box made from a container and silica gel solves the problem for less than one failed print costs.
Myth 9: 3D printing is slow
This claim ages faster than anything else on the list. Input shaping, higher-flow hotends and better motion planning algorithms mean prints that once took a night now finish in a few hours. More importantly, for a single part what counts is not print speed but the time from idea to finished piece — and there 3D printing beats any technology that needs a mould or tooling. If your printer is slow, check firmware and profile first, and only then blame the technology.
Myth 10: you need CAD skills to start
The vast majority of first prints are ready-made models from free libraries: brackets, organisers, adapters, spare parts. Modelling becomes necessary only once you want something nobody has designed — and then you start with simple solids, not professional CAD. Treat modelling as a second stage, not as a prerequisite.
What to choose instead of myths — settings for typical use cases
| Use case | Material | Key setting |
|---|---|---|
| Enclosure, organiser, interior part | PLA / PLA+ | 0.2 mm, 3 perimeters, 20 % infill |
| Mechanical part under load | PETG or nylon | 0.2 mm, 4–5 perimeters, 30 % infill, orient along the force |
| Part working outdoors | ASA | Enclosure, 4 perimeters, 20–30 % cooling |
| Visual prototype for shape review | PLA | 0.3 mm, 2 perimeters, 10 % infill |
| Gasket, bushing, flexible element | TPU | 0.2 mm, slow printing, minimal retraction |
| Heat-resistant indoor part | HT-PETG or ASA | 4 perimeters, slower first layer, no draughts |
The most common mistakes that follow from myths
Raising infill instead of perimeters. If a part breaks, raise perimeters to four first and only then consider higher infill.
Printing everything at 0.1 mm. You double print time and increase the risk of an aborted job without gaining strength.
Lowering temperature at the first sign of trouble. Before you drop the nozzle temperature, check whether the symptom is stringing (then lower) or delamination (then higher).
Throwing away a spool that "went bad". In nine cases out of ten the filament is simply damp and drying it is enough.
Buying a new printer instead of calibrating. Flow, e-steps and the first layer give a bigger quality jump than changing the machine model.
Treating PLA prints as biodegradable waste. They go into plastics; industrial composting is a separate and rarely available stream.
Judging filament by price. Check diameter tolerance and batch consistency, because those are what determine flow stability.
Frequently asked questions
Does 100 % infill give the strongest print?
Not in practice. For the same amount of material you gain more by increasing wall perimeters and choosing the right part orientation. Full infill lengthens the print, uses more filament and accumulates shrinkage stress.
Will PLA decompose in a home compost bin?
No. PLA is industrially compostable, under conditions of around 58 °C and controlled humidity. In a garden compost bin, in a garden or in landfill it will not decompose within any reasonable time — it behaves like ordinary plastic.
Does a thinner layer always mean a better print?
No. A 0.1 mm layer improves the look of detail, but roughly doubles print time and does not increase strength. For functional parts choose 0.2 mm by default.
Does expensive filament always print better than cheap filament?
No. Print quality is determined by diameter tolerance, batch consistency, raw material purity and how the spool is wound. Price is sometimes correlated with these, but it is not a guarantee.
Is drying filament overkill?
Not for hygroscopic materials. PETG, TPU and nylon absorb moisture within days, and it shows up as popping at the nozzle, a rough surface and worse layer adhesion. PLA is less sensitive, but it too loses quality after long unprotected storage.
How to check for yourself whether a piece of advice is a myth
There is one rule: change one parameter at a time and print the same model. It sounds trivial, but it is exactly the step we skip most often — we fix three things, the print comes out better and we have no idea which change did it. A small test cube or a simple part with a hole is enough; you do not need special calibration models.
The second rule concerns repeatability. If a difference shows up on only one print, it is probably chance — repeat the test, ideally on another day and with another spool. Air humidity, room temperature and a draught from the window can shift the result more than the parameter you are testing.
The third rule: write it down. A short note — "spool X, nozzle 215 °C, bed 60 °C, 4 perimeters, no delamination" — is worth more than all remembered conclusions put together. After a few weeks you have your own settings database that works on your hardware — and you stop depending on other people's, often outdated, advice.
Summary
All ten myths share one denominator: each replaces measurement with belief. A temperature tower, a flow calibration and a single test print settle more than an hour of reading forums — and they do it for your specific printer, your spool and your room. Start with those three tests and most "proven advice" will simply stop being necessary.
If you are looking for a material that forgives beginner mistakes while still working for functional parts, a good starting point is Porima Tough PLA — it keeps the printing ease of PLA with clearly better impact resistance. Once your projects move outdoors or start working under load or at higher temperatures, move on to technical filaments.