---
tag: g026
title: Mesh Validation Pattern
brief: Test the mesh and adjust.

experimental: true
since: 1.1.0
requires: G26_MESH_VALIDATION
group: calibration

codes: [ G26 ]

notes: |
  - Before 1.1.6 it only works with `AUTO_BED_LEVELING_UBL`.
  - Since 1.1.7 it 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
    optional: true
    description: Disable leveling compensation (otherwise, enable)
    values:
      -
        type: flag
  -
    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

examples:

---

`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.