PEI sheet care: what sticks too well and when to use acetone

Short answer

Clean a PEI sheet with 90% IPA for routine wiping, and keep acetone for Prusa's Smooth PEI sheet only, about once a month. Prusa says never to use acetone on textured or satin sheets. PETG, ABS, ASA and some other materials can bond too strongly to smooth PEI and tear it, so Prusa recommends a separating agent such as glue stick for them.

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Smooth, textured and satin sheets

A PEI sheet is a removable build plate with a PEI surface, which filament grips while hot and usually releases once cool. Prusa sells three surfaces that need different care: smooth PEI, textured and satin. The rules below are Prusa's for its own sheets. Other makers' PEI sheets need their own instructions, so check the maker of the sheet you have.

Prusa sheet	Acetone	Routine cleaning
Smooth PEI	About once a month only	90% IPA
Textured	Never	90% IPA
Satin	Never	90% IPA

Prusa says never to use acetone on its textured or satin sheets, and to use acetone on its Smooth PEI sheet only about once a month.^[1] It recommends 90% IPA for routine cleaning, and says not to use acetone before printing PETG.

What sticks too well

Smooth PEI is not good for every filament. Prusa warns that PETG, ABS, ASA, XT and CPH can stick too strongly to its Smooth PEI sheet and damage it, and recommends a separating agent such as a glue stick.^[1]

That is why a PETG part can lift a flake of the coating when you pop it off. The glue stick is not there to help the part stick; it is a release layer between the plastic and the PEI.

A simple rule from Prusa's advice:

1. PLA on smooth PEI: clean with IPA and print.
2. PETG, ABS, ASA, XT or CPH on smooth PEI: apply a separating agent first.
3. Unsure about a material: check the sheet maker's material list, or test on a corner of an older sheet.

A cleaning routine

• Before most prints: wipe the cool sheet with 90% IPA and a lint-free cloth.
• When IPA no longer restores grip on smooth PEI: acetone, no more than about monthly, and not right before PETG.
• Textured or satin: IPA only.
• Handle by the edges: keep fingers off the print area so you do not undo the cleaning.

Getting the right size

A replacement sheet must match the bed, not the build volume. ELEGOO lists the Neptune 4 Plus build volume as 320 x 320 x 385 mm and its PEI printing platform as 330 x 330 mm.^[2] The platform is larger than the print area, so a sheet ordered by the build volume would be too small. Look for the platform or plate size in your printer's spec table and match it, then check that the seller's sizing matches it too.

When to replace a sheet

We found no maker interval for replacing a sheet. Judge it by condition: a coating that is torn or worn through where you print, and that cleaning no longer brings back, is a reason to replace it.

Next

• Printer maintenance schedules from the makers
• Bed probes and bed mesh: first layer problems
• ELEGOO Neptune 4 versions and parts that fit
• Maintenance parts overview