---
tag: g026
title: Mesh Validation Pattern
brief: Test the mesh and adjust.
author: thinkyhead
contrib: soxhi8

group: calibration
since: 1.1.0
requires: G26_MESH_VALIDATION

codes: [ G26 ]

notes:
- Before 1.1.6 `G26` requires `AUTO_BED_LEVELING_UBL`.
- Since 1.1.7 `G26` also works with `MESH_BED_LEVELING` and `AUTO_BED_LEVELING_BILINEAR`.

parameters:

- tag: B
  optional: true
  description: Bed temperature (otherwise 60°C) to use for the test print.
  values:
  - type: int
    tag: temp

- tag: C
  optional: true
  description: Continue with the closest point (otherwise, don't)
  values:
  - type: bool

- tag: D
  type: flag
  optional: true
  description: Disable leveling compensation (otherwise, enable)

- tag: F
  optional: true
  description: Filament diameter (otherwise 1.75mm)
  values:
  - type: float
    tag: linear

- tag: H
  optional: true
  description: Hot end temperature (otherwise 205°C) to use for the test print.
  values:
  - type: float
    tag: linear

- tag: I
  since: 2.0.6
  optional: true
  description: Material preset to use for the test print. Overrides `S`.
  values:
  - type: int
    tag: index

- tag: K
  optional: true
  description: Keep heaters on when done
  values:
  - type: bool

- tag: L
  optional: true
  description: Layer height to use for the test
  values:
  - type: float
    tag: linear

- tag: O
  optional: true
  description: Ooze amount (otherwise 0.3mm). Emitted at the start of the test.
  values:
  - type: float
    tag: linear

- tag: P
  optional: true
  description: Prime Length
  values:
  - type: float
    tag: linear

- tag: Q
  optional: true
  description: Retraction multiplier. `G26` retract and recover are 1.0mm and 1.2mm respectively. Both retract and recover are multiplied by this value.
  values:
  - type: float

- tag: R
  optional: true
  description: Number of `G26` Repetitions (otherwise 999)
  values:
  - type: int

- tag: S
  optional: true
  description: Nozzle size (otherwise 0.4mm)
  values:
  - type: float

- tag: U
  optional: true
  description: Random deviation. (`U` with no value, 50).
  values:
  - type: float
    tag: linear

- tag: X
  optional: true
  description: X position (otherwise, current X position)
  values:
  - type: float
    tag: linear

- tag: Y
  optional: true
  description: Y position (otherwise, current Y position)
  values:
  - type: float
    tag: linear

---

`G26` Mesh Validation Pattern is designed to be used in conjunction with mesh-based leveling to test the accuracy of the probed mesh.

The `G26` command prints a single-layer pattern over the entire print bed, giving a clear indication of how accurately every mesh point is defined. `G26` can be used to determine which areas of the mesh are less-than-perfect and how much to adjust each mesh point.
