Bed surfaces compared

The plate you print on matters more than most settings. Here is what each surface is actually good at.

Textured PEI

The default on most modern machines, and the best all-rounder. Grips well hot, releases on its own as it cools, and leaves an attractive textured finish on the bottom of the print. Wears out eventually — when the texture polishes flat, adhesion goes with it.

Smooth PEI

Glassy bottom surface, excellent grip. Almost too much grip with PETG, which can pull chunks out of the sheet. Use a thin layer of glue stick as a release agent with PETG, not as an adhesive.

Glass

Dead flat and cheap, which is its main virtue. Needs glue or hairspray for anything to stick reliably, and parts can bond so hard when cool that the glass chips. Largely superseded by spring steel.

Spring steel with a magnetic base

Not a surface in itself but the mounting for one. Being able to lift the sheet out and flex it is the single biggest quality-of-life upgrade on an older machine.

How to make any of them last

• Wash with warm soapy water regularly — skin oil is the usual culprit and is invisible
• Isopropyl alcohol between prints, never on its own long-term
• Never use acetone on PEI
• Never scrape with anything metal
• If a glue stick suddenly fixes a plate that used to work, the surface is worn out