First Layer Troubleshooting - The Complete Guide

[Intermediate]

You’ve moved past your first print. Now your printer mostly works—except for that recurring nightmare: the first layer. Sometimes it’s perfect. Sometimes the print foundation is so weak it separates before layer 10. Sometimes the nozzle crashes into the bed and makes that horrible grinding sound.

Welcome to the intermediate stage of 3D printing. The good news: first layer problems are diagnostic. Once you understand what you’re looking at, you can fix it. This guide gives you the tools to identify, diagnose, and solve virtually any first layer issue.

Understanding the First Layer Problem Space

Before we solve problems, let’s be clear about what the first layer is actually doing. It’s doing three things simultaneously:

1. Creating adhesion: Your plastic needs to stick to the bed well enough to stay put as subsequent layers are deposited.
2. Setting the foundation: The first layer is where all subsequent layers build from. If it’s uneven, everything above it is compromised.
3. Establishing the outline: The first layer defines where your print exists in space. If it’s too wide or too narrow, dimensions are off.

Most first layer problems fall into one of these categories: adhesion failure, foundation unevenness, or dimension issues. Let’s solve them systematically.

The Diagnosis Flowchart: What You’re Actually Seeing

When your first layer goes wrong, what you see tells you exactly what went wrong. Use this flowchart to identify your problem:

Is plastic coming out of the nozzle at all?

• No → Extrusion Problem (section below)
• Yes, but very little → Partial Extrusion Problem
• Yes, but it’s too thin or broken → Adhesion or Height Problem
• Yes, but it looks like spaghetti → Adhesion Failure
• Yes, it looks good, but layers peel apart → Adhesion is weak (not visible initially)

Is the nozzle height correct?

• Too high: plastic doesn’t stick, creates thin broken lines
• Too low: nozzle scrapes the bed, makes grinding noises, may jam
• Uneven: sticks in some areas, fails in others

Does plastic stick to the bed?

• Sticks immediately and stays: probably too hot or surface too aggressive
• Doesn’t stick at all: bed too cold, surface too smooth, or nozzle too high
• Sticks inconsistently: height is uneven, surface is dirty, or temperature varies

Bed Leveling: The Foundation

I’m going to spend more time on this than any other topic because it’s the most common first layer problem.

The Paper Method (Traditional)

This is how most people level their beds, and it works reasonably well:

1. Heat the bed and nozzle to your printing temperature. This matters. A cold bed changes the distance between nozzle and surface.
2. Home all axes. Move the nozzle to its zero position.
3. Move to a corner of your bed (usually front-left), leaving about 20mm margin from the edges.
4. Slide printer paper under the nozzle. Standard copy paper is about 0.1mm thick.
5. Adjust the leveling screw until the nozzle grips the paper with slight resistance. You should be able to pull the paper out, but it takes deliberate force.
6. Repeat for all corners (usually 4, sometimes 9 for larger beds).
7. Check the center of the bed.
8. Do it again. Seriously. After adjusting one corner, the others shift slightly. One pass is never enough.

Specific technique: Turn each leveling screw slowly—about 1/4 turn at a time. Most printers use springs under the bed, so it takes a few adjustments to find the sweet spot. If you’re screwing counterclockwise and the nozzle goes up, remember that—don’t fight it.

The catch: The paper method is approximate. It gets you close, but “close” might be 0.05-0.1mm off, and that’s enough to cause problems.

The Feeler Gauge Method (More Precise)

If you’re printing a lot, consider a feeler gauge set (around 10-15). These give you precise gaps.

1. Use a 0.1mm gauge for tight tolerance printing (detailed miniatures, fine features).
2. Use a 0.15mm gauge for general printing (normal tolerance).
3. Use a 0.2mm gauge for loose, forgiving prints (decorative pieces, prototypes).

The process is identical to the paper method, but you get mechanical precision instead of guessing how much paper resistance feels right.

The Probe Method (If Your Printer Has It)

Printers like the Prusa Mini or Creality Ender 3 V2 can auto-level with a probe that touches the bed. If you have this feature:

1. Load the auto-leveling routine (this varies by printer—consult your manual).
2. The printer runs a grid pattern of measurements.
3. The firmware calculates the bed plane and compensates automatically.

This method is fast and accurate, but it’s only as good as your probe calibration. If you’re getting inconsistent results, check that your probe is clean and properly mounted.

Reality check: Even with auto-leveling, manually check one corner with the paper method. Probes can misread, get dirty, or drift over time.

Nozzle Gap Issues: Reading the First Layer

Once your bed is level, how do you know if the nozzle gap is actually correct? Look at the extruded line itself.

The Ideal First Layer Line

When your nozzle height is perfect for PLA at 205°C, the extruded line should:

• Be approximately 0.4mm wide (standard nozzle width)
• Have a semi-glossy surface (not rough, not mirror-shiny)
• Form a thin ribbon that bonds to the bed immediately
• Have clean edges without ooze

Nozzle Too High (>0.2mm above bed)

What it looks like:

• Thin, broken lines
• Plastic doesn’t stick—it peels up immediately
• Gaps between extrusion lines
• Sometimes the nozzle doesn’t extrude at all

Why it happens:

• Bed leveling was off
• Thermal expansion (bed was cold during leveling, hot during printing)
• Sagging bed surface (uncommon unless the bed itself is warped)

How to fix it: Lower the nozzle by turning your leveling screws (usually counterclockwise, but check your printer). Make small adjustments: 1/4 turn at a time. Print a test line and check again.

Pro tip: Some slicers have a “babystep” Z-offset feature that lets you adjust nozzle height mid-print without stopping. If you see the problem immediately (first 30 seconds), you can adjust on the fly.

Nozzle Too Low (<0.05mm above bed)

What it looks like:

• The nozzle drags across the bed or barely extrudes
• You hear a grinding or squealing sound
• First layer has almost no plastic (just squeezed plastic film)
• Subsequent layers peel off because the foundation is too thin

Why it happens:

• Over-tightened leveling screws during initial setup
• Bed deflection (the bed pushed down under the nozzle pressure)
• Thermal contraction (bed was hot during leveling, cooled during print)

How to fix it: Raise the nozzle carefully. Turn leveling screws counterclockwise (usually) in 1/4 turn increments. This is more delicate than lowering—too much and you’re back to “too high” problems.

Critical: Stop the print immediately if you hear grinding. Continuing damages the nozzle, bed, or both.

Uneven Height (Different at Each Corner)

What it looks like:

• One corner sticks perfectly, another corner has gaps
• Print succeeds in some areas, fails in others
• First layer has uneven thickness across the bed

Why it happens:

• Inadequate leveling (didn’t do enough passes)
• Warped bed (the bed itself isn’t flat)
• Loose bed mounts or springs
• Bed thermally warped from being too hot too long

How to fix it: Relevel the bed with more precision. Do at least 3 full passes (all 9 points if your printer has them). If problems persist:

1. Check bed flatness: Use a straight edge and look for gaps.
2. Check that all bed springs have similar tension (they should feel similar when you press on the bed at different points).
3. Check that the bed frame itself isn’t damaged or bent.

If the bed is warped, you might need a replacement bed or a thick PEI sheet overlay to bridge the warping.

Adhesion Issues: When the First Layer Sticks (Or Doesn’t)

You’ve leveled perfectly and the nozzle height is right, but plastic still won’t stick. That’s an adhesion problem, not a leveling problem.

Temperature-Related Adhesion

Bed temperature too cold:

• Symptom: Plastic sticks for 30 seconds, then peels
• Fix: Increase bed temperature by 5°C (PLA: 50→55→60°C; PETG: 70→75→80°C)
• Why it works: Warmer beds keep plastic pliable longer, allowing better bonding

Nozzle temperature too cold:

• Symptom: Plastic barely flows, creates thin weak lines
• Fix: Increase nozzle temperature by 5°C (PLA: 200→205→210°C; PETG: 240→245→250°C)
• Why it works: Hotter plastic flows better, wetting the bed surface more completely

Nozzle temperature too hot:

• Symptom: Plastic sticks well but oozes between lines, stringing occurs
• Fix: Decrease nozzle temperature by 5°C and increase print speed slightly
• Why it works: Cooler plastic sets faster, preventing ooze while maintaining adhesion

Surface-Related Adhesion

Dirty build surface:

• Symptom: Inconsistent adhesion in the same area
• Fix: Clean the bed with isopropyl alcohol and a lint-free cloth
• Why it works: Oil and dust prevent plastic from wetting the surface
• Frequency: Every 2-3 prints, or immediately if you see a failure

Textured surface worn smooth:

• Symptom: Used to stick fine, now doesn’t
• Fix: Rough the surface with fine sandpaper (400-600 grit) or replace the surface
• Why it works: Texture mechanically grabs plastic
• Prevention: PEI sheets last about 500-1000 prints before needing replacement

Bare glass bed:

• Symptom: Hit-or-miss adhesion even when everything else is right
• Fix: Use a textured build surface (PEI sheet, Textured PEX, or Garolite)
• Cost: 15-25 for a replacement sheet
• Why it’s worth it: Solves 80% of adhesion problems

Material incompatibility:

• Symptom: Some materials stick well, others don’t
• Fix: Match material to surface (PLA→textured PEI; PETG→textured PEI or glass; Nylon→PEI or painter’s tape)
• Why it varies: Different plastics have different surface energies

Material-Specific First Layer Tips

Different materials behave differently. Here’s what you need to know:

PLA (Polyester)

• Bed temperature: 50-60°C (I use 55°C as default)
• Nozzle temperature: 200-210°C (I start at 205°C)
• First layer speed: 50mm/s
• Adhesion trick: If it won’t stick, increase bed temp to 60°C first. PLA is picky about bed temperature.
• Common issue: Warping in corners if the room is drafty
• Solution: No draft, or add a simple cardboard enclosure around the printer

PETG (Polyethylene Terephthalate Glycol)

• Bed temperature: 70-80°C (I use 75°C as default)
• Nozzle temperature: 240-250°C (I start at 245°C)
• First layer speed: 40-50mm/s (slower than PLA)
• Adhesion trick: PETG sticks so well it sometimes won’t come off. Use a cold bed for removal.
• Common issue: Stringing and oozing at higher temperatures
• Solution: Stay below 250°C; increase print speed once past layer 1

TPU (Flexible Filament)

• Bed temperature: 60°C minimum (higher is often better)
• Nozzle temperature: 220°C (be precise; TPU is finicky)
• First layer speed: 20-30mm/s (half normal speed)
• Adhesion trick: TPU requires texture; bare glass won’t work
• Common issue: Stringing and blobbing
• Solution: Low nozzle speed, slightly lower temperature than you’d expect

ASA (Acrylonitrile Styrene Acrylate)

• Bed temperature: 100-110°C (this is hot—monitor for warping)
• Nozzle temperature: 245-260°C
• First layer speed: 40mm/s
• Adhesion trick: ASA sticks aggressively. Consider a release agent or easy-remove surface.
• Common issue: Requires ventilation (emits fumes)
• Solution: Print in a ventilated space or use a filter-equipped enclosure

Problem Diagnosis Flow

Use this to systematically eliminate causes:

Problem: First layer won’t stick

1. Is the bed hot? (Touch it carefully—don’t burn yourself. Should feel warm.)

   • No → Wait for bed to reach temperature
   • Yes → Continue

2. Is the nozzle height correct? (Can you slide paper under it with resistance?)

   • No → Relevel the bed
   • Yes → Continue

3. Is the build surface clean?

   • No → Wipe with isopropyl alcohol
   • Yes → Continue

4. Is the build surface textured?

   • No → Consider upgrading to PEI or textured surface
   • Yes → Continue

5. Is the nozzle temperature high enough?

   • Probably not → Increase by 5°C and retry
   • Unknown → Check your filament package for recommended range

Problem: First layer is uneven (sticks in some spots, not others)

1. Is the bed level?

   • Uncertain → Relevel with 3+ full passes
   • Yes → Continue

2. Is the build surface warped?

   • Visually check with a straightedge
   • If warped → Upgrade bed or add overlay

3. Are all bed springs tight and uniform?

   • Check by pressing on bed at different spots
   • Should have similar resistance everywhere

Problem: Nozzle crashes into or scrapes the bed

1. Stop immediately (do not continue).
2. Let the nozzle cool.
3. Raise it by 0.2-0.3mm using leveling screws.
4. Heat and try again.
5. If problem persists, check that the bed frame is mounted securely (no loose bolts).

Pro Tips from the Trenches

Tip 1: Level at printing temperature. A cold bed is a different geometry than a hot bed. Thermal expansion matters. Level while the bed is already at 55°C (or whatever your target is).

Tip 2: Trust the paper method, but verify. After leveling, print a simple pattern (a 50x50mm square with 0 infill) and watch the extrusion. If it’s perfect, you’re done. If something’s off, adjust.

Tip 3: Keep a leveling log. Write down what worked:

• “Front-left corner: 2.5 turns”
• “Front-right: 2.75 turns”
• “Center: 2.6 turns”

The next time you need to relevel, these notes give you a starting point instead of guessing.

Tip 4: Use a feeler gauge if you’re serious. The 5-10 investment pays for itself in saved filament and time.

Tip 5: Clean the nozzle regularly. Bits of plastic stuck to the nozzle affect flow and temperature readings. Wipe it with a wet (not soaked) cloth while it’s hot before each print.

Tip 6: Change bed temp, not nozzle temp, for first layer sticking. Bed temperature has a bigger impact on adhesion than nozzle temperature. Try 5°C bed adjustments before tweaking the nozzle.

The Takeaway

First layer troubleshooting is a process of elimination. You’re gathering information: Is the bed level? Is the height right? Is the temperature correct? Is the surface clean?

Work through these systematically, not randomly. Change one variable at a time. Print, observe, adjust.

After 50 prints, you’ll know exactly what your specific printer needs. You’ll level your bed in 2 minutes without thinking. Your first layer will be so reliable you won’t even think about it.

That’s the goal. Get to the point where first layer problems are so rare you forget they used to be a thing.