Printing Guide
Bed Adhesion Guide
Getting filament to stick to the bed is the most common problem in 3D printing. Most fixes take under a minute once you know what's actually wrong.
Why First Layer Adhesion Fails
Adhesion depends on two things: surface energy and mechanical keying. Surface energy is the molecular attraction between molten plastic and the bed surface. Mechanical keying is the physical interlocking between slightly squished filament and the texture of the build plate. Every adhesion fix improves one or both of these.
When a print detaches mid-way, it's because the internal stress of the cooling plastic overcame the adhesion force holding it to the bed. The stress is mostly from thermal contraction — plastic shrinks as it cools, and the edges want to pull inward and upward. Materials with higher shrinkage rates (ABS, Nylon, PC) have the worst adhesion problems, not because they don't stick, but because they pull harder once they do.
Surface Energy
Molecular attraction between molten filament and the build plate. Higher surface energy = better wetting = stronger bond. Oils from your fingers destroy this.
Mechanical Keying
Molten plastic flows into micro-textures and hardens in place. Why textured PEI grips so well — and why smooth glass needs adhesives for most materials.
Thermal Contraction
As layers cool, they shrink. Edges contract inward and lift — warping. The bigger the part, the stronger the force. ABS shrinks ~0.8%, PLA ~0.3%.
Check These First
Most adhesion failures aren't about the bed surface. They're a dirty plate, wrong Z-offset, or bed temp that's 10°C off. Fix those first before buying anything.
Bed Surfaces Compared
Your build surface determines most of your adhesion experience. Each one works well with certain materials and fails in predictable ways with others.
| Surface | Best For | Avoid | Release | Notes |
|---|---|---|---|---|
| Smooth PEI (spring steel) | PLA, ASA, ABS | PETG (bonds permanently) | Parts pop off when plate cools | The default on most modern printers. Clean with IPA between prints. |
| Textured PEI | PETG, PLA, ABS | TPU (won't release) | Flex plate to pop off | Best all-rounder. The texture prevents PETG from bonding permanently. Gives a matte bottom finish. |
| Glass (borosilicate) | PLA (with adhesive) | ABS, Nylon without enclosure | Wait for full cool-down | Perfectly flat. Needs glue stick or hairspray for most materials. Heavy — slower acceleration. |
| Glass + PEI sheet | Same as smooth PEI | Same as smooth PEI | Cool-down release | Aftermarket PEI sticker on glass. Cheaper alternative to spring steel. |
| FR4 (garolite) | Nylon, PA6, PA12 | Not ideal for PLA | Good natural release | The go-to for Nylon. Fibreglass composite that Nylon grips without permanent bonding. Prusa sells these. |
| BuildTak / PEX | PLA, ABS | PETG (will damage surface) | Peel while warm | Adhesive sheet applied to existing surface. Wears out over time. Good budget option. |
| Painter's tape (blue) | PLA, PETG | ABS, Nylon | Peel tape off | The original bed surface. Still works. Cheap, easy to replace. No heated bed required for PLA. |
If you're buying one plate: Textured PEI on spring steel. Best all-round surface right now. It handles PLA, PETG, ABS, and ASA without adhesives. The only materials that need something different are Nylon (get FR4) and TPU (use smooth PEI with a release agent).
Bed Temperature by Material
Bed temp controls how fast the first layer solidifies. Too cold and the filament hardens before it wets the surface. Too hot and the bottom layers stay soft — you get elephant's foot (a bulge at the base) and the part can shift during printing.
These are starting points. Your filament may need ±5°C — check the spool label first.
| Material | Bed Temp (°C) | First Layer | Notes |
|---|---|---|---|
| PLA | 55–65 | Same | Over 70°C causes elephant's foot and soft base. Some PLA sticks fine at 50°C. |
| PETG | 70–85 | Same or +5 | Higher than PLA. On smooth PEI, use glue stick as a release agent or PETG will fuse to the plate. |
| ABS | 95–110 | 100–110 | Needs enclosure. Below 95 you'll get corner lifting within 10 layers. |
| ASA | 95–110 | 100–110 | Same as ABS. ASA is slightly less warp-prone but still needs enclosed printing. |
| TPU | 45–60 | 50–60 | Too hot and TPU sticks permanently to smooth PEI. Lower is usually better. |
| Nylon (PA6/PA12) | 70–90 | 80–90 | Warps aggressively. FR4 plate + enclosure + glue stick is the proven combo. |
| PC | 105–120 | 110–120 | Highest bed temps. Enclosure mandatory. Magigoo PC or Nano Polymer adhesive. |
| PLA+ | 55–65 | Same | Same as PLA. The "plus" is about impact resistance, not adhesion behaviour. |
Why "too hot" is as bad as "too cold": An overheated bed keeps the bottom layers soft for too long. The nozzle drags through them, creating elephant's foot, rough texture, and dimensional inaccuracy. If your first layer looks good but the base is bulging, lower bed temp by 5°C before adjusting anything else.
Surface Prep & Cleaning
A single fingerprint on your build plate can cause a failed print. Skin oils reduce surface energy enough that filament won't wet the surface. Cleaning is the most overlooked adhesion fix.
Cleaning Agents
Isopropyl Alcohol (IPA) 90%+
Wipe with a lint-free cloth between every print. Removes fingerprints and light residue. Use 90% or higher — 70% IPA is 30% water and leaves mineral deposits behind. Skip the scented or "with moisturiser" variants.
Dish Soap & Warm Water
Every 10–20 prints, or whenever IPA stops working. Gets the accumulated oils and film that IPA just smears around. Scrub with a sponge, rinse well, dry completely. This is the answer when "I cleaned it with IPA and it still won't stick."
Acetone (PEI only)
Nuclear option. Once a month on PEI sheets, or when soap doesn't help. Strips the surface back to fresh PEI. Do not use on textured PEI powder coat — it can damage the texture. Do not use on glass, BuildTak, or painted surfaces.
Common Contaminants
Fingerprints
Number one cause. Handle plates by the edges only. After a failed print, clean before retrying — you touched the surface pulling off the failed part.
Filament Residue
Thin film of plastic left after part removal, especially PETG. Builds up over time. IPA doesn't remove it — use dish soap or a plastic scraper.
Spray Lubricants
WD-40, silicone spray, or PTFE lubricant overspray from maintenance. Migrates to the build plate and causes total adhesion failure. Clean rails away from the printer.
Adhesive Buildup
Old glue stick or hairspray layers that have gone lumpy. Causes uneven first layers. Wash off completely with warm water and start fresh.
Adhesion Aids
Adhesion aids do two opposite jobs: they can increase adhesion (glue on glass for ABS), or act as a release agent (glue on smooth PEI for PETG). Knowing which role the aid is playing tells you whether you need it or whether it's masking a dirty plate.
Glue Stick (PVA)
Elmer's purple or any PVA school glue. Apply a thin even layer, let it dry. On PEI, it acts as a release agent for PETG — prevents permanent bonding. On glass, it acts as an adhesion promoter for PLA and ABS. Reapply every 3–5 prints. Wash off with warm water when it gets thick.
Hairspray (unscented, extra hold)
Aqua Net Extra Super Hold is the community go-to. Gives a tacky PVA-like layer on glass. Spray from 20cm away for an even coat. Downsides: overspray gets on rails and bearings, builds up fast, and your workspace smells like a salon. Glue stick is easier to control.
Magigoo
Purpose-built adhesion pen. The material-specific variants (Magigoo PA for Nylon, Magigoo PC for polycarbonate) work noticeably better than generic PVA. More expensive but cleaner to apply and lasts longer per coat. Worth it for Nylon and PC.
Painter's Tape
Blue 3M painter's tape. Fresh surface every print, and PLA sticks to it without heat. Replace when it tears or loses grip. Only real option if you don't have a heated bed. Limited to PLA and some PETG — anything above 80°C bed temp melts the tape adhesive.
When adhesion aids mask a real problem: If you need glue stick for PLA on a PEI sheet, something else is wrong. PLA should stick to clean PEI with no adhesive at all. Check your Z-offset, bed temp, and whether the plate is actually clean. Save adhesion aids for the materials that genuinely need them: PETG on smooth PEI (as release agent), Nylon, PC, and glass beds.
First Layer Settings
Slicers have separate settings for the first layer because it needs different treatment — slightly squished, slightly wider, slightly slower. Here's what to tune.
Z-Offset (Live-Z)
Fix This Before Anything Else
Z-offset controls the gap between the nozzle and the bed on the first layer. Too high: filament sits on the surface like a loose rope — no squish, no adhesion. Too low: the nozzle scrapes the bed, filament can't extrude, and you get thin transparent lines or nothing at all. Correct Z-offset produces lines that are slightly wider than the nozzle diameter, with no gaps between adjacent lines and no transparency. Adjust in 0.02mm increments while printing a first-layer test pattern.
Speed, Flow & Width
First Layer Speed
15–25 mm/s is standard. Slower gives filament more time to wet the surface and adhere. Even on a Bambu running at 300mm/s, don't rush the first layer — it's 30 seconds of a multi-hour print.
First Layer Flow
100–105% flow for the first layer. Slight over-extrusion fills gaps. If you need more than 110%, your Z-offset is probably too high — lower the nozzle instead of cranking flow.
First Layer Width
120–150% of nozzle diameter. Wider lines = more contact area = better adhesion. A 0.4mm nozzle should extrude ~0.5–0.6mm wide on the first layer. Most slicers default to this.
First Layer Temp
Running the first layer 5°C hotter than the rest helps filament wet the surface better. Not always necessary but worth trying when nothing else is working.
Skirt, Brim & Raft
Skirt (default)
Outline printed around (but not touching) the part. Primes the nozzle and lets you eyeball Z-offset before the real print starts. 2–3 loops. Does NOT help adhesion — it's diagnostic only.
Brim
A single-layer extension of the first layer, printed outward from the part perimeter. Increases the surface area of the first layer by 5–10x, which cuts warp forces at corners and edges. Use 5–8mm brim width for warp-prone parts. First thing to try for ABS/ASA corners lifting. Easy to remove with a deburring tool or knife.
Raft
A thick multi-layer platform printed under the part. Maximum adhesion but rough bottom surface and wasted material. Use only when a brim isn't enough (warped bed, tiny contact area). If you need a raft on a modern printer with mesh levelling, something else is wrong.
Material-Specific Adhesion
Each material behaves differently on the bed. These are what actually work, not just what the spool label says.
PLA & PLA+
Sticks to everything. Clean PEI at 60°C with no adhesive is all you need. If PLA won't stick, your bed is dirty or your Z-offset is wrong — don't reach for glue. PLA actually sticks too well to smooth PEI sometimes; wait for the plate to cool fully before removing. PLA+ behaves identically for adhesion.
PETG
Use textured PEI or apply glue stick to smooth PEI. PETG will permanently bond to bare smooth PEI — you'll tear chunks out of the PEI sheet trying to remove the part. This is the #1 reason people destroy PEI plates. Bed at 75–80°C. First layer Z-offset slightly higher than PLA (less squish) — PETG is stringy and doesn't like being over-squished.
ABS & ASA
Both shrink significantly and require an enclosure for anything larger than ~50mm in any dimension. Bed at 100–110°C. Use a brim on all parts — corners will lift without one. ABS slurry (dissolved ABS in acetone) on glass beds is an old trick that still works. ASA is slightly less warp-prone but still needs the same setup. Draft shields in the slicer help if you can't fully enclose.
TPU (Flexible)
Sticks well to almost everything — sometimes too well. Smooth PEI at 50°C. The problem with TPU is usually removal, not adhesion. Print slow (20–30mm/s first layer). On textured PEI, TPU can lock into the texture permanently. If you print TPU often, keep a separate smooth plate and use a thin layer of glue stick as a release agent.
Nylon (PA6, PA12)
The worst for adhesion. Nylon soaks up moisture fast, so dry your filament first — wet Nylon won't adhere no matter what bed setup you have. Use an FR4 (garolite) plate at 80–90°C with Magigoo PA or glue stick. Enclosure recommended. Brim always. PA12 (like Bambu PA6-CF) is somewhat easier than raw PA6 but still warps on large parts.
The moisture factor: Nylon, PETG, and TPU are all hygroscopic. If a material that used to stick fine suddenly won't, the filament may have absorbed moisture. Dry it before blaming the bed. Nylon: 70°C for 12+ hours. PETG: 65°C for 4–6 hours. TPU: 50°C for 4 hours. Full storage & drying guide →
Troubleshooting
Don't change five things at once. Match the symptom to the cause, fix that one thing, test.
Corners Lifting (Warping)
Sharp corners concentrate thermal stress. Try in order: add a brim (5–8mm), bump bed temp by 5°C, enclose the printer (even a cardboard box works for ABS), enable draft shield in your slicer. For PLA, this usually means the bed is too cold or there's a draft — don't print next to an open window or AC vent.
Entire Print Detaches Mid-Print
Z-offset too high (not enough squish), dirty plate, or wrong bed temp. Recalibrate Z-offset first. If it only happens in one area, your bed isn't level — run mesh levelling or re-tram.
Elephant's Foot (Base Bulge)
First few layers are wider than the rest. Bed too hot, Z-offset too low (over-squishing), or first layer flow too high. Lower bed temp by 5°C. If that doesn't help, use "elephant foot compensation" in your slicer (0.1–0.2mm) — it insets the first layer perimeter to compensate.
Part Stuck Too Well (Can't Remove)
Wait for the plate to cool completely — PLA releases from PEI at room temperature due to differential thermal contraction. If still stuck: put the plate in the freezer for 5 minutes. For spring steel plates, flex the plate. Never use a metal scraper on PEI — use a plastic spatula. If this happens repeatedly, your Z-offset is too low or bed temp too high.
PETG Fused to Smooth PEI
Classic mistake. PETG at 80°C bonds chemically to bare PEI. The fix is prevention: always use textured PEI for PETG, or apply glue stick to smooth PEI before printing. If it's already fused, try heating the bed to 90°C and using a plastic scraper carefully. You may lose some PEI surface — sand it smooth with 1000-grit and carry on.
First Layer Won't Stick in One Spot
Uneven bed. Run mesh levelling if your printer supports it. On manual-level printers, re-tram all four corners. Aluminium beds can have a ~0.3mm bow from the factory — mesh levelling compensates for this. Glass is always flat if you want to skip the software fix.
Stringing on First Layer
If the first layer has thin strings between travel moves, the nozzle is too high. Lower Z-offset by 0.02–0.04mm. The first layer should be pressed into the bed enough that the nozzle doesn't ooze during short travels.
References
- Prusa Knowledge Base — First Layer Calibration guide. help.prusa3d.com/article/first-layer-calibration-i3_112364
- Prusa Knowledge Base — Print Surface Preparation. help.prusa3d.com/article/print-surface-preparation_2210
- All3DP — 3D Printer Bed Adhesion: All You Need to Know. all3dp.com/2/3d-printer-bed-adhesion-all-you-need-to-know
- Teaching Tech — Bed levelling and first layer calibration tool. teachingtechyt.github.io/calibration.html#firstlayer
- Magigoo — Material-specific adhesion products. magigoo.com
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