What temperature do you print PEI at?

PEI prints at a nozzle temperature of 370-410C with the bed at 140-180C. Start at the lower end of the nozzle range and raise it in 5C steps until layers bond cleanly.

Does PEI need an enclosure?

Yes. PEI needs an enclosure. Without one the part cools unevenly, corners lift off the bed and layers split partway up the print.

What is PEI good for?

PEI suits aerospace and rail interiors where flame rating matters, continuous service near 170C, chemically aggressive environments. Avoid it for any printer without a 400C hot end and a heated chamber, hobby budgets, beginners.

How much does PEI cost?

A 1 kg spool of PEI typically sells for $200-500. That is an indicative street price rather than a live figure, so check the retailer for today's cost.

PEI print settings

Polyetherimide, sold as ULTEM · Expert

PEI (Polyetherimide, sold as ULTEM) prints at 370-410°C with the bed at 140-180°C. It needs an enclosure. Dry the filament before printing.

An aerospace-grade thermoplastic with a UL 94 V-0 flame rating and a glass transition around 186C. It needs a 400C hot end and a heated chamber, so it is machine-limited rather than skill-limited.

Settings at a glance

Nozzle

370-410°C

Bed

140-180°C

Enclosure

Required

Part cooling

Retraction

1-2mm

Typical price

$200-500 / kg

Ranges are typical manufacturer-published figures for this material class, not measurements we took. Always start with your filament maker’s own numbers where they differ. The price is an indicative street price for a 1 kg spool, not a live quote.

Good for

Aerospace and rail interiors where flame rating matters
Continuous service near 170C
Chemically aggressive environments

Avoid for

Any printer without a 400C hot end and a heated chamber
Hobby budgets
Beginners

The problem people actually hit

A heated bed is not a heated chamber. Large parts delaminate partway up even at the right nozzle temperature, because the chamber needs to hold 120-180C for the layers to fuse.

Drying

Dry at 120-150C for several hours. This is a laboratory oven, not a filament dryer, and skipping it produces visible voids.

Buying PEI

PEI is an industrial material and general retailers are not a serious source for it. Buy from a specialist who publishes the datasheet, at a price high enough that the wrong spool is an expensive mistake. Typical street price is $200-500 per 1 kg spool.

Check before you order

Diameter 1.75mm unless your printer takes 2.85mm. Check before ordering, not after.
Published diameter tolerance. ±0.02mm is good, ±0.05mm is loose and shows up as inconsistent extrusion.
Vacuum-sealed with desiccant. Hygroscopic filament that shipped open has already absorbed moisture and will need drying before its first print.
Confirm you have an enclosure before buying. Without one this material will warp regardless of spool quality.

Specialist suppliers

MatterHackers

Deep engineering-material catalogue and published spec sheets, including grades general retailers do not stock.

Printed Solid

Specialist stockist with strong coverage of nylon and carbon-fibre filled materials.

Named because they stock this class of material and publish specifications. We have no commercial relationship with either, and these are ordinary links.

Not sure this is the right material? Compare all materials.

What you need to print PEI

Gear that PEI genuinely requires, with the specification that decides whether a given unit will actually work.

High-temperature oven

Must hold 150C steadily

PEI needs drying well above what any consumer filament dryer reaches. This is lab oven territory, not a spool warmer, and it is one of the reasons the material is impractical on a desktop setup.

See high-temperature oven on Amazon

Printer enclosure

Fully closed, with a door

PEI warps when a draught cools the part unevenly. An enclosure holds chamber heat steady, which fixes lifting corners and split layers more reliably than any slicer setting.

See printer enclosure on Amazon

Bed adhesion

PEI sheet sized to your bed, or a PVP glue stick

PEI lifts at the corners before it fails anywhere else. A textured PEI surface plus a thin glue layer holds the first layer down while the chamber comes up to temperature.

See bed adhesion on Amazon

Airtight storage with desiccant

Sealed container plus rechargeable desiccant

Drying a spool once achieves nothing if it sits open afterwards. Storage is what keeps the filament usable between prints.

See airtight storage with desiccant on Amazon

As an Amazon Associate we earn from qualifying purchases. Links above are affiliate links, and using them costs you nothing extra.

PEI questions

What temperature do you print PEI at?: PEI prints at a nozzle temperature of 370-410C with the bed at 140-180C. Start at the lower end of the nozzle range and raise it in 5C steps until layers bond cleanly.
Does PEI need an enclosure?: Yes. PEI needs an enclosure. Without one the part cools unevenly, corners lift off the bed and layers split partway up the print.
Do you need to dry PEI?: Dry at 120-150C for several hours. This is a laboratory oven, not a filament dryer, and skipping it produces visible voids.
What is PEI good for?: PEI suits aerospace and rail interiors where flame rating matters, continuous service near 170C, chemically aggressive environments. Avoid it for any printer without a 400C hot end and a heated chamber, hobby budgets, beginners.
How much does PEI cost?: A 1 kg spool of PEI typically sells for $200-500. That is an indicative street price rather than a live figure, so check the retailer for today's cost.

PEI or PEEK?

PEEK (Polyether Ether Ketone) prints at 370-420°C with a 120-160°C bed and needs an enclosure. The polymer family used in aerospace and in medical implants, though a spool of printing filament carries no such certification itself. It needs a 400C hot end and a heated chamber, so it is out of reach of nearly every consumer printer.

Read the PEEK settings guide →