3D Printer Filament

Buy PLA. Any mainstream 1 kg spool of it, in whatever color you like. That is the whole answer for your first month, and every source we read on beginner printing says the same thing. If you want a brand, our picks are here.

Why PLA and not something better

PLA is not the strongest plastic, or the most heat-resistant, or the one used for anything structural. It is the one that prints. It goes down at temperatures every printer can reach, it sticks to a plate that is barely warm, it does not shrink much as it cools, and it does not need an enclosure or a fume extractor. Almost every failure a beginner hits with a fancier material is a failure PLA would not have produced.

The plastics people move to next each solve one specific problem. PETG survives heat and flexes rather than snapping, which matters for anything that lives in a car or outdoors. TPU is rubbery, for phone cases and gaskets. ABS and ASA are for parts that need to take real heat, and both want an enclosure to stop them peeling off the plate as they cool. None of them is an upgrade in a general sense. Each is a trade.

The three numbers worth reading on a spool

Diameter and tolerance. Filament is 1.75 mm on almost every desktop machine sold today. The tolerance — usually quoted as plus or minus 0.02 or 0.03 mm — is how consistent that thickness is along the spool. A wide tolerance means the printer is pushing slightly more or less plastic than it thinks, which shows up as inconsistent surfaces.

The temperature range. Every reputable manufacturer publishes a nozzle range and a bed range. It is worth a glance because it tells you whether your machine can print it at all, and because the top of the range is where you go when layers are not bonding.

How it is packaged. Filament absorbs water out of ordinary room air. A spool that arrives vacuum sealed with a desiccant pack is dry when you open it; one that has been sitting in an open box may not be. Wet filament pops, strings and prints badly, and it is responsible for a large share of the failures beginners diagnose as machine problems. That is what the storage and drying page is about.

What decides the price of a spool

Very little of it is the plastic. Mainstream PLA from any of the well-known brands is chemically much the same; you are paying for consistency, for winding quality — a badly wound spool tangles and ruins a print eight hours in — and for whether the manufacturer publishes real data rather than marketing bullets. Specialist filaments cost more for genuine reasons: silk and matte finishes, carbon-fiber fill that needs a hardened nozzle, or a spool tag your printer can read.

Buying five kilograms of one color to save money per kilogram is a classic first-month mistake. You will change your mind about color, and filament degrades in an open room. Two spools is a sensible start.

How much a print actually uses

Less than people expect, which is the pleasant surprise of this hobby. Filament is sold by weight, your slicer tells you the grams before you press print, and the arithmetic is a division you can do in your head: spool price divided by 1,000, times the grams on the screen. We work that through with the numbers on what filament costs per print, and it feeds into the full first-month cost breakdown.

Where filament and failure meet

If a print stops sticking to the plate, the filament is the second thing to check, not the first — a dirty plate is more likely. But it is a genuine cause, particularly for PETG and particularly for a spool that has been open for a month. The bed adhesion page works through the causes in order of likelihood and cost, and the PETG section there is the one filament owners come back for.