3D printing · Guide
3D Print Not Sticking to the Bed? Fix the First Layer
The first layer makes or breaks a print. If it does not stick, nothing above it matters: the part pops loose, drags around the plate, and turns into a tangle of plastic spaghetti. The good news is that almost every "it would not stick" problem comes from a short list of causes, and they fall in a predictable order. Work down them from the top, and most first-layer failures are fixed before you reach the bottom.
Nozzle too far from the bed (leveling and Z-offset)
This is the most common cause by a wide margin. The first layer has to be gently squished into the plate, not laid down in thin air. If the nozzle sits too high, the filament comes out as round strands that barely touch the surface and peel away the moment the nozzle drags past them. Get this right and half your adhesion problems disappear.
Start by leveling the bed. On a manual machine, that means setting the gap at each corner with a sheet of paper, turning the knobs until you feel a light drag on the paper as the nozzle passes over it. On a printer with auto bed leveling (ABL, a probe that maps the surface), run the mesh routine, but understand that ABL corrects for a tilted or warped bed, it does not set how close the nozzle sits. That is the Z-offset, and it is a separate number you still have to dial in.
Set the Z-offset by lowering the nozzle in small steps, around 0.02 to 0.05mm at a time, while the first layer prints. Watch the lines. A good first layer looks slightly flattened, with each line pressed into a flat-topped ribbon and the lines just touching their neighbors so the surface looks solid with no gaps. A bad first layer is either round, shiny, separated strands you can see daylight between (nozzle too high) or a smeared, translucent, ridged mess with plastic squeezing up the sides of the nozzle (nozzle too low). Aim for the middle: flat lines that kiss, no gaps, no ridges.
A dirty bed
Even a perfectly leveled plate will reject a print if it is greasy. Fingerprints and skin oils are the usual culprit, and they kill adhesion on PEI and glass faster than anything else. You touch the plate to pull off the last print, and the oil from your fingers leaves a patch the next layer slides right off.
Clean the surface with isopropyl alcohol (IPA), 90% or higher, on a lint-free cloth or paper towel, and wipe the whole plate before a print. For glass, an occasional proper wash with dish soap and warm water cuts grease that IPA alone smears around, then dry it fully. And the habit that prevents the problem: stop touching the print surface with bare fingers. Handle the plate by its edges, and if you need to clear a stuck part, clean the spot afterward.
Wrong bed temperature
Each filament has a bed temperature window where it grips. Too cool and it will not bond, too hot and it stays molten and shifts. These are the typical starting points.
| Filament | Typical bed temp |
|---|---|
| PLA | ~60C |
| PETG | ~70 to 80C |
| ABS | ~100 to 110C |
| ASA | ~100 to 110C |
One trap with the hotter materials: ABS and ASA also need an enclosure to hold a stable chamber temperature. Without one, the corners lift no matter how hot you set the bed, because the bed only warms the bottom while the air around the part stays cold and pulls it apart as it cools. A hot bed is necessary for ABS and ASA, but it is not enough on its own.
First layer printing too fast or too cool, or too much cooling
Speed and cooling fight adhesion in their own ways. A first layer printed too fast does not give the plastic time to flow into the texture of the plate and bond, so slow the first layer down. Many slicers have a dedicated first-layer speed setting; drop it to around 15 to 25mm/s and let the rest of the print run at normal speed once the base is down.
The part cooling fan is the other enemy of the first layer. Its job is to set plastic quickly for clean overhangs higher up, but on the first layer that same fast cooling stops the plastic bonding to the bed and to itself. Keep the part cooling fan off for the first layer or two. This matters most for PETG, ABS, and ASA, which all want little to no part cooling anyway, but even PLA bonds better with the fan off at the base.
Warping pulling the corners up
Sometimes the first layer goes down fine and sticks, then the corners curl up off the plate partway through the print. That is warping, not an adhesion failure in the usual sense. As the part cools it contracts, and the contracting upper layers pull hard enough on the base to peel the corners loose. It hits ABS and ASA hardest, because they shrink the most as they cool.
The fixes target the cooling, not the plate. Use an enclosure to keep the chamber warm so the part cools slowly and evenly. Add a brim or a raft for more grip around the edges where the lifting force is worst. Turn on a draft shield in the slicer to keep stray air off the part, and keep the part cooling fan off. If a material warps no matter what you try, that behavior is often the material itself, not your setup; the filament types guide covers how PLA, PETG, ABS, and ASA each behave and which ones fight you.
The build surface and adhesion aids
The plate itself shapes how much help you need. Textured PEI grips most filaments well and leaves a pleasant matte bottom; smooth PEI gives a glossy bottom and very strong adhesion, sometimes too strong. Glass gives the flattest, shiniest first layer but needs more help to grip in the first place. Each handles a clean wipe and the right temperature differently, so match the aid to the surface.
When the basics are right and a part still will not hold, reach for an aid. A glue stick (plain washable PVA) gives extra grip on glass and works as a release layer for PETG on PEI, where PETG bonds so hard it can tear chunks out of the sheet; the thin glue film lets the part come off without damage. A brim, a single-layer skirt printed attached to the part, adds footprint for small or tall parts that have little contact area. A raft, a printed base the part sits on, helps with warpy materials or a bed that is slightly uneven, at the cost of more filament and a rougher bottom. And as an old-school option, painter's tape (blue masking tape) laid across the bed gives PLA a toothy surface to grab when nothing else is on hand.
First-layer checklist
- Level the bed (manual paper-drag or run the ABL mesh).
- Set the Z-offset so the first-layer line is slightly squished, flat and just touching its neighbors.
- Clean the plate with IPA, and wash glass with soap and water now and then.
- Set the right bed temp for the filament (PLA ~60C, PETG ~70 to 80C, ABS and ASA ~100 to 110C).
- Slow the first layer down to around 15 to 25mm/s.
- Turn the part cooling fan off for the first layer or two.
- Add a brim or a touch of glue stick if the part still needs more grip.
What a failed layer costs you
A first layer that does not stick is not free to get wrong. Every failed start is wasted filament and wasted machine time, and on a long print a fail four hours in stings. The 3D print cost and pricing calculator accounts for exactly this with a failure buffer: it adds a percentage on top of each print to cover the ones that do not make it, so the price you charge still leaves you whole after a bad first layer eats a spool's worth of plastic and an afternoon.