A print that won’t stick to the bed is the most common thing that goes wrong on a 3D printer, and almost every time it’s one of a handful of causes. Work through them in order and the first one on the list fixes most cases before you ever touch a setting.
So before you start changing temperatures and re-slicing, go down this list top to bottom. It’s roughly in order of how often each thing is actually the culprit.
Clean the plate first (it’s grease, usually)
Nine times out of ten a print that won’t stick is a dirty plate. Every time you handle the build plate you leave a thin film of skin oil on it. You can’t see it, but it’s enough to keep the first layer from grabbing.
Wash the plate with dish soap and warm water in the sink, scrub it with your fingers or a soft sponge, and dry it with a clean paper towel. Not a shop rag that’s been wiping down the printer, a clean one. Isopropyl alcohol (90%+) works as a quick wipe between prints, but it smears the oil around as much as it removes it, so a real soap-and-water wash every so often does more.
Handle it by the edges after that. If you press your thumb right where the print goes, you just undid the wash.
Check your first-layer squish (Z-offset)
If the plate is clean and it still won’t stick, the next suspect is the gap between the nozzle and the bed on that first layer. Too high and the lines sit as loose round strands that never bond to the plate. You want them squished flat and fused into a solid sheet.
I wrote a whole separate guide on reading and setting this, because it’s the single most important first-layer setting and it deserves its own walk-through: how to calibrate your Z-offset. If your first layer looks gappy or the lines are round and separated, start there.
Is the bed hot enough?
Most plastics need a warm bed to stick, and the right temperature depends on the material. Cold bed, no grip. Here’s what I run:
- PLA bed: 55°C
- PETG bed: 80°C
- ABS/ASA bed: 110°C
- TPU bed: 50°C
Those are the numbers I run, not gospel. Your specific filament brand will have a recommended range printed on the spool or the box, and if it disagrees with mine, trust the spool.
One gotcha: some slicers let the first layer start before the bed is fully up to temp if you’ve turned off the “wait for bed” step. Make sure the bed has actually reached the set temperature before the nozzle starts laying plastic.
Slow down the first layer
If the first layer is racing across the plate, it doesn’t have time to press into the surface and bond before the nozzle has moved on. A slow first layer sticks better, full stop.
Set your first-layer speed down around 20 to 30 mm/s even if the rest of the print rips along at 200+. You only pay the time cost once, on layer one, and it buys you a foundation the rest of the print stands on. Most slicers have a separate “first layer speed” setting for exactly this reason.
Match the plate to the filament
Not every build surface likes every material, and this trips up a lot of people who just bought a second plate.
- Textured PEI grabs PLA and PETG well and gives the bottom a matte finish. PETG can grab it a little TOO well (more on that below).
- Smooth PEI gives a glassy bottom finish and is great for PLA, but some filaments slide right off it when it’s cold and weld to it when it’s hot.
- Glass or a bare plate almost always wants a glue stick as the actual adhesive.
If you’ve got the wrong pairing, no amount of temperature tuning fully fixes it.
The PETG exception: use glue to keep it OFF the plate
PETG is the one material where you might add glue stick to make a print stick LESS. On a bare textured or smooth PEI plate, hot PETG bonds so hard it can rip a chunk of the plate coating off when you remove the part. A thin layer of plain glue stick acts as a release layer so the part pops off without taking the plate with it. Do this before you print PETG on PEI, not after you’ve already fused it on.
Level and tram the bed
If the print sticks fine in the middle but lifts at the corners or one edge, or it sticks on one side of the plate and not the other, that’s a leveling problem, not an adhesion problem. The nozzle is the right height in one spot and too far away in another.
Run your printer’s bed leveling or auto mesh routine. If it’s a manual bed, tram it (adjust the corner screws so the bed is physically level to the nozzle) before you rely on any mesh to paper over the difference. A mesh can compensate for a small amount of unevenness, but it can’t save a bed that’s badly out of level.
Warping: it’s sticking, then peeling
Sometimes the first layer goes down fine and then a corner curls up off the plate part way through the print. That’s warping. The plastic stuck at the start and let go later, as it cooled and shrank, and that shrinking force pulls the corners up off the bed.
Warping hits ABS and ASA hard, PETG sometimes, and PLA rarely. The fixes are about controlling the cool-down:
- Keep drafts off the print. A window or an AC vent blowing across the bed will curl an ABS corner every time. An enclosure (even a cardboard box over the printer for a test) holds the chamber warm and still.
- Turn the part-cooling fan down or off for ABS. That fan helps PLA and hurts high-temp materials by cooling them too fast.
- Add a brim in the slicer. A brim is a single-layer skirt fused to the part’s edges that adds surface area right where the corners want to lift.
When you actually need a brim or glue
If you’ve cleaned the plate, set the squish, got the bed temp right, and it’s a small-footprint or tall-skinny part that doesn’t have much plastic touching the plate, then reach for the adhesion helpers:
- A brim adds contact area around the base and peels off after. Good for parts with tiny footprints.
- Glue stick (plain washable school glue) on glass or a bare plate is the real adhesive there, and on PEI it’s a release layer for PETG as covered above.
These are the last resort, not the first move. If you need a brim on every single print, something earlier in this list is off. Fix that instead of leaning on the brim forever.
Work down the list in order and most “it won’t stick” prints are solved by the time you’ve cleaned the plate and set the squish. The rest come down to matching the surface to the material and keeping the corners from cooling too fast.