First Layer Check

Run a simple one-layer test and use it to set Z-offset (nozzle-to-bed gap), confirm even extrusion, and catch bed/mesh issues early. You’re aiming for slightly flattened lines that fuse together, stick everywhere on the plate, and don’t show ridges from over-squish.

TL;DR

Print a one-layer square and adjust live Z/Z-offset until the lines are slightly flattened, touch with no gaps, and don’t have plowed-up ridges. If one side looks different, fix tramming/bed mesh before chasing flow or temperature.

A quick visual map of the main decisions behind first layer check.

What You Are Checking (and Why It Works)

The first layer is a controlled “squish” test. The nozzle presses hot plastic into the surface so it wets the bed and each line fuses to its neighbor. Too much gap and the filament stays round and barely bonds; too little gap and the nozzle plows the bead, causing ridges, roughness, and sometimes skipped steps or poor dimensional accuracy.

Fast First-Layer Procedure (10 minutes)

  1. Clean the build surface: remove fingerprints, dust, and old adhesive (use the cleaner that matches your surface).
  2. Preheat nozzle and bed to normal printing temperatures, then wait 2–3 minutes so the bed temperature stabilizes.
  3. Start a first-layer test: a single-layer square/rectangle that spans several areas of the bed (a big skirt/brim also works).
  4. Watch the first 2–3 lines: decide “too high,” “too low,” or “just right” from line shape and adhesion.
  5. Adjust one thing only: live Z/Z-offset is the main knob during the test. Make a small change, then re-check the same area of the pattern.
  6. Let the full first layer finish and compare center vs corners vs edges to confirm consistency across the bed.

What You See vs What It Means

Lines are round, not flattened
Nozzle too high (gap too large) or under-extruding.
Gaps between lines
Usually too high; can also be low flow or a partial clog.
Lines don’t stick / peel up
Often too high or bed is dirty; also bed too cool or cooling/drafts too strong.
Ridges, rough scraping, plowed edges
Nozzle too low (over-squish) or a local high spot in the bed.
Very glossy smear / “elephant skin”
Too low; the bead is being over-compressed and wiped.
One side good, other side bad
Bed not trammed/leveled, warped plate, or bed mesh not applied/loaded.

If It Still Fails

Sticks in one area, releases in another

Likely cause: Bed not trammed/leveled, warped bed, or bed mesh not enabled/loaded

Fix: Re-tram the bed, then run bed mesh and confirm it is active for the print (correct profile/start g-code).

Adhesion suddenly got worse compared to last week

Likely cause: Build surface contamination or surface wear

Fix: Deep-clean the surface (correct solvent for the plate), then refresh adhesive strategy or replace/flip the surface if worn.

First layer looks thin/thick in waves while Z seems correct

Likely cause: Extrusion inconsistency: partial clog, wet filament, or incorrect temperature

Fix: Purge and inspect the nozzle, verify temps for the material, and dry filament if stringy/popping or inconsistent.

Perfect squish but corners still lift/curl

Likely cause: Cooling too strong, bed too cool, drafts, or high-shrink material

Fix: Reduce cooling for layers 1–3, increase bed temp slightly, add a brim, and block drafts around the printer.