HT-PLA filament guide
HT-PLA, short for high temperature PLA, is PLA formulated so it can be annealed: baked after printing until the plastic crystallizes. As printed it behaves much like ordinary PLA. After annealing it holds its shape at temperatures that would slump a standard PLA part, while still printing on any machine with no enclosure. It is the easiest route to heat resistant parts if you are willing to add a bake step.
How HT-PLA gets its heat resistance
Standard PLA comes off the printer mostly amorphous, which is why it softens around 55 to 60°C. HT-PLA is designed to crystallize readily when heated, so a controlled bake reorganizes the plastic into a more crystalline structure that stays rigid at much higher temperatures. Polymaker, for example, lists a heat deflection temperature of about 108°C for its HT-PLA Pro after a 30 minute anneal at 100°C.
The one thing not to get wrong
The heat resistance only comes after annealing. An HT-PLA part straight off the printer softens at roughly the same temperature as normal PLA. If you skip the bake, you have paid extra for ordinary PLA.
Printing it
HT-PLA prints like PLA, often a little hotter. Expect a nozzle around 210 to 230°C and a bed around 50 to 65°C, with no enclosure and no hardened nozzle needed. Start from your normal PLA profile, raise the nozzle temperature slightly and follow the maker's recommended range for your spool.
Because it prints so easily, HT-PLA is a practical step up for anyone with an open frame printer who needs parts that survive heat but does not want to deal with ABS or ASA fumes and warping.
Annealing it
Annealing means holding the finished part at a set temperature, commonly around 95 to 110°C depending on the brand, for a set time, then letting it cool slowly. A kitchen oven works, but ovens swing in temperature, so check with a separate thermometer and do a test piece first.
Parts can change size slightly as they crystallize, shrinking in some directions and growing in others, and thin unsupported sections can sag. Test with a calibration piece before annealing anything with tight tolerances, and support delicate parts in sand or salt while they bake.
When to choose HT-PLA
Choose HT-PLA for heat exposed parts where you want PLA's easy printing and fine detail: brackets in a warm car interior, parts near electronics or motors, enclosure fittings and tooling. Some newer grades, such as Polymaker's HT-PLA Pro, also roughly double impact strength, which greatly reduces the brittleness of earlier HT-PLA.
Skip it when the part never sees heat, since standard PLA or PLA+ is cheaper, and when you cannot anneal. For parts that need toughness more than stiffness, PETG is usually the better buy, and for full sun outdoors, ASA remains the safer choice. The heat resistant filament guide compares all the options.
Compare PLA Prices
HT-PLA is listed with the rest of the PLA family. Compare live PLA listings by brand, weight and price per kg, and check a specialty grade's premium against standard PLA before you buy.
Compare PLA Prices