When a corner lifts, note when it happens. A first layer that never attaches properly needs a different starting check from a base that prints cleanly and curls upward later. More glue or a hotter bed is not a universal answer to both.
If the loose part can move into the nozzle’s path, stop the job using the printer’s controls. Diagnose on the cooled part and the next small test rather than pressing a lifting print back down during operation.
Did it fail immediately or curl later?
BCN3D’s first-layer guidance distinguishes poor initial attachment from a piece that curves after printing has progressed. Its discussion also separates lifted areas from elephant’s foot, where the base spreads outward. Use the observed shape and timing to choose your first investigation.
The first lines never attached reliably
Check the correct sheet profile, documented first-layer calibration and preparation for that surface/material pair. Inspect whether failure is widespread or concentrated in one area. Do not compensate indefinitely by moving the nozzle closer: excessive squish can create a different defect or make removal damaging.
The first layer looked good, then the corner rose
Record when and where lifting began, including proximity to a draft and whether the change coincided with different cooling. Focus on the material’s thermal environment, geometry and appropriate adhesion support. Preserve a photograph of the first layer if you have one.
Prepare the plate for this material
Start with the maker’s instructions for the actual plate. Cleaning and release-layer requirements vary; a treatment suitable for one coating may be unsuitable for another. The PEI cleaning guide covers that task separately. Also confirm that the printer is using the intended sheet or calibration setting after a plate change.
Adhesive is part of a material-and-surface combination, not a universal upgrade. BCN3D’s examples use different adhesive choices for different polymers. Avoid stacking several products on the plate merely because the previous print lifted; that makes both the adhesion and the next cleaning result harder to interpret.
Cooling advice must follow the polymer
Prusa’s warping guidance connects cooling and contraction with lifting, particularly on large high-temperature-material prints. It also warns that cooling demands differ: protecting ABS or ASA from drafts is not an instruction to make every PLA print hotter. Too much or too little cooling can create problems in different situations.
Use an enclosure only as permitted by your printer and material instructions, including ventilation and equipment limits. Do not cover the machine with an improvised bag or disable safeguards to retain heat. If you change a cooling parameter, inspect the rest of the print for lost layer bonding or deformed small features, not just the corner that originally lifted.
A brim and a draft shield solve different problems
- Brim: adds first-layer area around the model to help attachment.
- Draft shield: creates a surrounding printed wall to reduce the effect of drafts for suitable materials.
- Skirt: a separate outline normally used to establish extrusion before the model; an ordinary short skirt is not an attached brim.
Those distinctions follow PrusaSlicer’s skirt-and-brim documentation. Preview the generated feature so you know which one you enabled. Account for brim removal on a fitted edge, and do not assume a larger brim will solve every thermal or calibration problem.
Make the next test answer one question
Keep the material, model and baseline profile recorded. Choose one change supported by the failure’s timing and repeat a representative part of the geometry.
The base stays flat
Check the rest of the part and its dimensions before adopting the change for the long print. Flatness alone is not the complete acceptance criterion.
The same corner still lifts
Keep the result and move to the next plausible cause. If the available printer, plate and environment cannot meet this material’s requirements, reconsider the geometry or formulation instead of escalating heat and adhesion indefinitely.
