Warping
Warping is when the corners or edges of a print lift off the bed because the plastic shrinks as it cools.
Why it matters
A warped print can come loose mid-print and fail, or finish with bent edges. Prusa says it usually comes from a sudden difference between the melting temperature at the nozzle and the surrounding air.
It affects high-temperature materials most, such as ABS and ASA. Large objects lift more easily too.
Prusa’s fixes start with the surroundings. Keep the ambient temperature stable, because drafts from windows or air conditioning units make warping worse. An enclosure or a draft shield helps hold the heat.
If your printer sits in an air-conditioned room, check for a draft where it stands. Move it away from the vent before you change other settings.
Adhesion matters as well. Prusa advises cleaning the print surface with isopropyl alcohol of 90% or stronger and trying a thin layer of glue stick. A hotter heated bed also helps.
Prusa also suggests brims, and warns that too much print cooling can separate layers, so adjust fans carefully.