Material Grade

LW-PLA Lightweight Foaming PLA

PLA with a foaming agent that cuts printed weight roughly in half. The grade RC plane builders swear by, shown as LW-PLA on our deals cards.

Last updated: July 2026


LW-PLA (lightweight PLA) contains a heat-activated foaming agent. Print it hot enough (usually 230-260°C) and it expands to two or even three times its extruded volume. You compensate by cutting flow to 40-60%, and the result is a printed part with the same outer dimensions at roughly half the density of standard PLA: about 0.6-0.8 g/cm³ instead of 1.24.

This is a specialist grade with one dominant community: RC aircraft. A wing printed in single-wall LW-PLA is light enough to fly and stiff enough to survive landings, which regular PLA simply cannot do at flyable weight. The same properties make it interesting for cosplay armor (large pieces, wearable weight) and props, where the slightly foamy matte surface even helps hide layer lines.

The trade-off is tuning. Foaming rate depends on temperature, so every spool needs a flow-calibration tower: print test sections at increasing temps, measure wall thickness, and set flow for your chosen temp. Skip that step and you get either gaps (under-extrusion) or blobbed, over-inflated walls. colorFabb invented the grade and their documentation is still the best starting point; eSUN's ePLA-LW is the budget option that made it mainstream.

LW-PLA at a glance
Printed density
~0.6-0.8 g/cm³ at full foam (standard PLA is 1.24)
Foaming temp window
Starts ~220°C, peaks 240-260°C depending on brand
Flow compensation
40-60% at full foam. Calibrate per spool with a flow tower
Speed
Slow: 20-40 mm/s. Foaming needs time in the melt zone
Typical use
RC planes (single-wall wings), cosplay, props, weight-critical parts
Strength
Foamed walls are weaker per mm than solid PLA. Design with geometry, not infill
LW-PLA vs standard PLA

Weight is the only reason to buy it. At full foam a part weighs 40-55% of its solid-PLA equivalent, which transforms anything that flies and helps anything that gets worn. Strength per wall-millimeter drops, so LW-PLA designs lean on geometry (curved skins, ribs, spars) instead of brute-force perimeters.

Cost per printed part is friendlier than the per-kg price suggests: you are extruding half the mass, so a €40 spool of LW-PLA goes roughly twice as far as its weight implies. It is still a premium product; check the live table below because prices swing between €30 and €45/kg.

If you only want a matte, layer-line-hiding surface and not the weight savings, matte PLA gets you the look for a third of the price with none of the tuning. LW-PLA earns its cost only when grams matter.

Who makes LW-PLA, and today's prices

colorFabb LW-PLA (the original, best documentation), eSUN ePLA-LW (the value pick, usually €30/kg), Polymaker, Spectrum, and Recreus. All are in the live price table below.

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Frequently Asked Questions

What is LW-PLA filament?
LW-PLA is PLA with a heat-activated foaming agent. Printed at 230-260C it expands 2-3x, so with flow reduced to 40-60% you get parts at roughly half the density of standard PLA. RC aircraft builders are its main audience.
How do I calibrate LW-PLA?
Print a flow/temperature tower: sections at increasing temps, single-wall, then measure wall thickness with calipers. Pick the temp where foaming is consistent and set flow so a single wall matches your slicer's line width. Recalibrate for each new spool.
Is LW-PLA strong?
Per millimeter of wall, foamed LW-PLA is weaker than solid PLA. Designs compensate with geometry: curved single-wall skins, internal ribs and spars. For flying weight-to-stiffness it beats every solid filament, which is why RC wings use it.
Can I print LW-PLA without foaming?
Yes. Below about 220C it prints like slightly soft normal PLA at 100% flow. Some builders do this deliberately for spars and joints in the same print material, then foam the skins.
Why is LW-PLA so expensive?
The foaming chemistry and a smaller market keep it at 30-45 euros per kg. Remember you extrude roughly half the mass per part, so effective cost per print is closer to twice-the-price-of-PLA than the sticker suggests.
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