Why Prints Lose Adhesion
Bed adhesion failures fall into two categories that look similar but have different causes and different fixes. The first is the print never sticking in the first place — it slides around or pops off within the first few layers. The second is the print sticking fine initially, then lifting at a corner or edge later in the print, sometimes hours in.
The first kind is almost always a first-layer problem: a dirty surface, wrong Z-offset, or bed temperature too low for the material to bond. The second kind is usually warping — the plastic itself shrinking as it cools, pulling the corners up off the bed with enough force to overcome whatever adhesion you had.
These need different fixes. Cleaning your plate won't stop ABS from warping, and an enclosure won't help if the issue is a fingerprint on a PETG print. Work through this guide in order — it goes from the fastest, most common fixes to the more involved ones, and tells you which category each fix addresses.
If the print doesn't stick within the first 2-3 layers, skip to Cleaning and Leveling. If it sticks fine but a corner lifts later in the print, skip to Brims & Cooling — that's warping, not an adhesion problem.
Build Plate Types Compared
What your build plate is made of has a bigger effect on adhesion than almost any setting. If you're still on the plate that came with a budget printer years ago, upgrading it can solve adhesion problems that no amount of tuning will fix.
| Surface | Adhesion (bare) | Finish | Best for |
|---|---|---|---|
| Smooth PEI | Good for PLA/PETG, needs help for ABS | Glossy | PLA, PETG, display pieces |
| Textured PEI | Excellent — most materials | Matte, lightly textured bottom | Everyday use, all-round (Bambu/Prusa default) |
| Glass | Poor without adhesive | Glossy, very flat | PLA with glue stick, mirror-finish bottoms |
| Garolite / FR4 | Excellent for nylon, TPU | Slightly rough | Engineering filaments, high-temp materials |
| Cool plate (Bambu) | Good for PLA/PETG/TPU | Textured | Lower-temp materials, easy release |
If your printer takes swappable plates — Bambu Lab's AMS-compatible printers support cool, engineering, and high-temp plates — matching the plate to the material is one of the highest-leverage changes you can make. A high-temp plate handles ABS/ASA/PC at 100°C+ bed temperatures far better than a stock cool plate, which can start to deform above 80-90°C.
Fix 1: Clean the Plate Properly
This is the single most common fix, and the most frequently skipped. Even a single fingerprint leaves behind skin oils that are invisible to the eye but completely block filament from bonding to PEI or glass.
Wipe the plate with isopropyl alcohol (90%+ concentration) and a lint-free cloth or paper towel, every single print session — not just when adhesion fails. Let it fully evaporate before starting the print. This single habit fixes more adhesion issues than every other fix on this page combined.
Avoid touching the print surface with bare fingers when loading a new plate or removing a print. If your PEI sheet has been heavily used and alcohol no longer restores adhesion, it may be glazed — a light scuff with a Scotch-Brite pad (in the direction of the texture, for textured sheets) can restore grip. If that doesn't work, the sheet has reached end of life and needs replacing; PEI sheets typically last 200-500 prints depending on materials used.
Fix 2: Bed Level and Z-Offset
If the first layer is too far from the nozzle, the filament doesn't get pressed into the surface and has almost nothing to grip. Too close, and the nozzle scrapes the plate, pushes filament around instead of laying it down, or gouges the surface.
Most modern printers — Bambu Lab, Prusa MK4, Creality K-series — have automatic bed leveling and even automatic Z-offset (flow calibration / first-layer mesh). If you're on one of these, run the full calibration sequence rather than skipping it to save time; a stale mesh from months ago is a common silent cause of patchy adhesion across the bed.
On printers with manual leveling, level cold (some printers expand slightly when heated, but for most consumer machines leveling at room temperature is fine) using a sheet of paper at each corner — you should feel slight resistance when sliding the paper under the nozzle. Then fine-tune Z-offset in 0.02-0.05mm steps based on how the first layer looks, not how it sounds.
Fix 3: Bed Temperature by Material
Bed temperature isn't just about preventing warping — it's the main thing controlling whether the bottom layer actually melts into the build surface and bonds chemically, not just mechanically. Too cold, and the first layer cools before it can bond.
| Material | Bed temp | Notes |
|---|---|---|
| PLA | 55-60°C | Higher than 65°C can cause elephant's foot on some plates |
| PETG | 70-80°C | Can bond too well — release issues common above 80°C |
| ABS | 90-110°C | Enclosure strongly recommended above 100°C |
| ASA | 90-110°C | Similar to ABS; less warping but still benefits from enclosure |
| TPU | 30-50°C | Some setups print fine on an unheated bed with a textured surface |
| Nylon | 70-90°C | Needs garolite or a strong adhesive — nylon barely sticks to PEI |
PETG bonds so well to PEI at high bed temperatures that it can permanently weld to the sheet, peeling off chunks of coating when removed. If you're seeing this, drop bed temperature by 5°C, or let the bed cool to room temperature before removing the part — PEI's release properties improve dramatically as it cools.
Fix 4: When to Use Adhesives
On a clean, properly leveled textured PEI plate, PLA and PETG generally don't need any adhesive at all. Reaching for glue stick or hairspray as a first response often just adds a cleanup step without addressing the actual problem — clean the plate first.
Adhesives earn their place in three specific situations:
- ABS, ASA, and nylon — these materials have weaker natural adhesion to PEI than PLA/PETG. A thin, even layer of washable PVA glue stick gives a meaningful boost.
- A worn or glazed build surface — as a stopgap until you replace the sheet, glue stick can restore enough grip to get through a print.
- Glass beds — glass alone has poor grip for most filaments, so glue stick or a thin layer of hairspray (PVA-based, not the resin/shellac kind) is close to mandatory.
Apply adhesive thin and even — a few light passes in a crosshatch pattern, not one thick coat. Too much glue can actually reduce adhesion by creating a slippery layer between the plastic and the plate, and adds unnecessary cleanup. Reapply every few prints, not every single one, on a sheet that's holding adhesive well.
Fix 5: Brims, Rafts, and Cooling
If the print sticks fine for the first several layers but a corner lifts later — that's warping, not an adhesion failure, and the fixes are different. Warping happens because the outer layers cool and shrink faster than the still-warm interior, and that shrinkage pulls the part's edges upward with enough force to overcome the bed bond.
A brim is the cheapest fix and works for almost any material — it's a single-layer ring printed around the base of the model, widening the footprint that's actually touching the bed without changing the part itself. It's especially effective on parts with a small footprint relative to their height, or sharp corners, which are the geometries most prone to lifting.
For PLA and PETG, a brim alone usually solves corner lifting. For ABS and ASA, combine a brim with reduced part-cooling and, if possible, an enclosure — even a simple cardboard box or acrylic panel kit around the printer reduces drafts and keeps the ambient temperature around the print more stable, which is what actually prevents the differential shrinkage that causes warping.
Rafts — a sacrificial layer printed under the whole model — are mostly obsolete on modern printers with good bed leveling and auto-calibration. They use significantly more filament and time than a brim and rarely solve a problem a brim and clean plate don't already fix. Reserve rafts for unusually difficult geometries: very small or pointed contact points, or printing directly onto a surface you know is imperfectly flat.
The overwhelming majority of "my print won't stick" problems are solved by an isopropyl alcohol wipe and a fresh leveling/calibration pass — not by buying a different filament or a fancy adhesive. Do those two things before anything else, every time.
If the print sticks initially and lifts later, that's warping, and no amount of cleaning fixes it. Add a brim, reduce cooling on the first few layers for ABS/ASA, and consider an enclosure if you print warp-prone materials regularly.
And if you've cleaned, leveled, set the right bed temperature for your material, and you're still fighting adhesion — it's probably time to replace the build surface. PEI sheets don't last forever, and a worn one will fight you no matter how careful you are with everything else.