3D Printing

I clean my print surface with some isopropyl alcohol between prints and then wash the sheet every so often with warm water and dish soap. I use a satin textured sheet rather than a Pei one on my Mk3, most prints self release when cool but petg does leave some residue, IPA cleans that nicely. I did use a Pei sheet in the past which I used gluestick on, largely because I do a lot of printing with petg and the one time I said eh it'll be fine I ripped a chunk of the surface off with the print, gluestick definitely works for a clean release, and I found I didn't need to reapply every print.

For really stuck on stuff, like an early cancellation, I have a plastic scraper. Using that and flexing the sheet back and forth until I can get under a corner is enough to pop it off. Usually it's the lead in purge that prusa slicer starts with that I need to do this with. A quick clean after than and it's good for the next print.

As a bed scraper, I use a putty knife that I've sharpened on one side (chisel grind, #4).

Before printing too-sticky materials (like TPU on my PEI bed), I put down a layer of glue stick. This is sticky enough for successful prints, but easily removed at the end of the print.

Maybe you are leveling the bed too close to the nozzle. Google some pictures of how a good first layer is supposed to look like and move the bed a little lower so that the first layer has good adhesion but isn't forced into the bed.

Using a gluestick on the bed isn’t just to help create good adhesion. It also acts as a barrier between the hotbed and the part. This greatly helps with part removal.

Chances are you are squishing too much first layer, so adjust that first. Then print over residue with slow speed and 5-10° hotter than usual settings. Residue should come off with print.

I would recommend a PEI print surface like this: https://www.amazon.ca/gp/product/B08L39BFVJ

Most of my bed adhesion issues (too much or too little) went away once I got this.> Ender 3 S1

EDiT: I should say I only ever printed with PLA since I got the PEI sheet. I know PETG can bond to a PEI surface, so be careful with that.

If it's glass, you can try putting it in freezer for a few minutes, but overall this is a common issue. If it becomes too common for you, upgrading to a flex steel bed is pretty great.