Wash or wipe the plate, then check the slicer has the right plate type and the bed temperature your filament’s maker specifies. Those two fix most first layers, and Bambu Lab’s first layer guide says outright that cleaning alone “solves most issues related to adhesion”. Nozzle height comes third, and lowering it to force adhesion is the one move Prusa explicitly tells you not to make.
Clean the plate, the way its maker says
Grease from fingers and tools is what both makers are fighting. They agree on the goal and disagree on the method, because their surfaces differ.
Prusa’s first layer troubleshooting article says isopropyl alcohol at 90 percent or stronger is the best degreaser for its smooth, satin and textured sheets. It warns against IPA sold for skin or nails, which can contain oils and moisturizers. Dish soap and warm water, “not hot”, is the backup for when IPA stops working, to be used rarely. Acetone is for the smooth PEI sheet only, about once a month, never before PETG, and never on textured or satin sheets. Prusa also makes a point worth a habit: if you do not touch the surface with your hands or dirty tools, you do not need to clean it before every print.
Bambu goes the other way and recommends washing its plates with hot water and detergent before printing, and not touching the surface afterward.
Neither is wrong. They are instructions for different coatings. Follow the one for the plate you own, and if you run a third-party plate, find its maker’s page before you reach for acetone.
Pick the right plate type in the slicer
This one is specific to printers whose slicer knows about plates, and it catches people who swap plates without telling the software. Bambu explains two consequences. The same filament gets a different bed temperature depending on the plate selected, so the wrong choice can leave the bed too cool. And because the Textured PEI plate has a granular surface, the printer lowers the nozzle by 0.04 mm after leveling when that plate is selected. Print on a textured plate with a smooth one selected and the nozzle runs 0.04 mm high. On a 0.2 mm first layer that is a fifth of the layer height gone.
Bed temperature by material
These ranges come from maker data sheets. Brands disagree, sometimes by 30 °C for the same polymer, so use your brand’s figure where you have it. Every row is on the temperature table.
| Material | Bed range across data sheets | Examples |
|---|---|---|
| PLA | 25 to 60 °C | Bambu PLA Basic 35 to 45 °C, Prusament PLA 40 to 60 °C |
| PETG | 65 to 90 °C | Bambu PETG HF 65 to 75 °C, Prusament PETG 70 to 90 °C |
| ABS | 80 to 100 °C | Bambu ABS 80 to 100 °C, Polymaker PolyLite ABS 90 to 100 °C |
| ASA | 70 to 115 °C | Overture 70 to 95 °C, Prusament 105 to 115 °C |
| TPU 95A | 30 to 50 °C | Bambu TPU 95A HF 30 to 35 °C |
| PA6 nylon | 50 to 90 °C | Overture Easy Nylon 50 °C, eSUN ePA 70 to 90 °C |
| PC | 90 to 110 °C | Bambu PC 90 to 110 °C |
Here is how that plays out. You have been printing Bambu’s PLA Basic, whose data sheet gives a bed of 35 to 45 °C, and the profile sits at 40 °C. You load Prusament PLA, whose data sheet says 40 to 60 °C, and keep the old profile. You are now at the very bottom of the new filament’s range. If corners lift, the first thing to try is the middle of Prusament’s window, 50 °C, before you blame the plate. Going the other way matters too: 60 °C is above the top of Bambu’s range for its own PLA, and PLA data sheets put heat deflection at 54 to 60 °C, so a bed that hot is holding the bottom of the part right at its softening point.
Prusa’s general rule for unfamiliar materials that will not stick is to raise the bed by 5 to 10 °C.
Check the printer can reach the number. Prusament’s ASA data sheet asks for 105 to 115 °C, while Bambu’s A1 mini specification lists a maximum bed temperature of 80 °C. The printer database has the bed maximum for every machine we list.
Too much adhesion is also a first layer problem
Prusa flags a group of filaments that bond too well to smooth PEI: PETG, ABS, ASA, and its XT and CPH copolyesters. Its table is blunt that IPA plus PETG makes the print adhere so strongly that removal can be extremely difficult, and that you can damage the sheet. The fix is a separating layer of ordinary PVA glue stick. No special 3D printing glue is needed, Prusa says, and superglue is never a substitute. It also suggests glue as an adhesion aid for nylon, PC and flexibles, and says it is not needed for PLA.
Bambu similarly recommends its glue when printing non-PLA materials on the Smooth PEI plate.
So glue stick does two opposite jobs depending on the pairing: release agent for PETG on smooth PEI, grip for nylon. If you are about to print PETG on a smooth sheet you just degreased to perfection, put the glue on.
Nozzle height and Z offset
Too high and the line is laid on the plate without being pressed into it. Too low and, in Prusa’s description, the nozzle blocks its own opening and no plastic comes out for the first layer or two.
On printers with manual adjustment, Prusa’s procedure is its First Layer Calibration with Live Adjust Z. Then the warning, in bold in the original: avoid compensating for a lack of adhesion by setting a lower Live Adjust Z. Squash too far and the nozzle can damage the steel sheet and cause excessive vibration, and Prusa notes that damage from an incorrect Live Adjust Z is not covered by warranty. If the layer looked right last week and does not stick today, the height did not change. The plate got dirty.
On printers that probe the bed themselves, the equivalent step is to re-run leveling. Bambu says that in rare cases an old calibration is inaccurate and gives patchy adhesion, recommends running bed leveling from the calibration menu with a clean nozzle tip, and strongly recommends leaving the per-print bed leveling option switched on. For Prusa’s load cell machines (MK4, CORE One, XL) the checklist is different again: make sure the nozzle is seated at the correct height in the Nextruder, and that a tight spool is not pulling on the extruder while the printer levels.
A plate that is not flat defeats any single Z value. Prusa’s temporary fix is a piece of paper under the low area of the sheet, and the proper one is the firmware’s bed level correction. Prusa also says to check that the sheet is seated properly, is not bent, and has no leftover filament trapped under it.
Slow the first layers down
If everything above checks out, Prusa suggests dropping speed to about 75 percent for the first three layers and then returning to normal. On its printers that is a turn of the knob during the print. In a slicer, the same thing is a first layer speed setting: if yours is 40 mm/s, try 30 mm/s.
Brim before glue
Prusa’s advice is to try a brim before adding adhesives, because it increases the surface area of the first layer. The plastic it uses is small change, which the print cost calculator will confirm.
If it still will not stick
One less obvious cause remains. Prusa lists a full or partial clog among first layer faults: debris in the nozzle, plastic left hot in the extruder for too long, or poor hotend cooling all cut the flow. If the spool has been sitting out, rule out moisture as well with the filament drying guide. If the first layer goes down well and the corners lift hours later, that is warping, which is about enclosure and chamber temperature; the outdoor materials comparison covers it for ABS and ASA.
