PLA: density, print temperature and when to choose it

PLA (polylactic acid) is the material almost everyone starts with in 3D printing. It is made from renewable feedstock (corn or sugarcane starch), needs no enclosure and forgives sloppy settings — which is why it is the default choice on most FDM printers.

Key properties

Density feeds directly into cost calculation: knowing the model volume from your slicer and the material density, you get the part weight in grams — and from that, the material cost of a specific job.

When to use it

• Prototypes and visual models where impact strength and heat resistance don't matter.
• Decor, souvenirs, miniatures — PLA holds fine detail well.
• One-off or display pieces — it prints faster and fails less often than ABS/ASA.

When to pick something else

• The part will sit in the sun or in a car in summer — PLA softens at around 55–60°C; go with ASA instead.
• You need impact strength or threaded joints under load — look at PETG or ABS.
• The part has to flex — you need TPU.

Pros and cons

Pros: low print temperature (less energy heating the bed and nozzle), almost no odor, minimal shrinkage (fewer bed-adhesion failures), the most predictable material to tune a print profile for.

Cons: low heat resistance (deforms in hot water or sunlight), brittle under impact loads, degrades in everyday conditions slower than people assume (industrial composting ≠ garden compost).

How it affects your print cost

A lower print temperature means less time and energy spent heating the bed and nozzle per print cycle — for equal print time, PLA usually costs slightly less in electricity than ABS/ASA with an enclosure and a 100°C+ bed. The filament itself typically costs less than engineering plastics (nylon, polycarbonate) and about the same as PETG.