Dimension (TAMS High Gloss)

Dimension (D) – High gloss mode

Definition

Dimension (D), also referred to as Dominant Structure Size, indicates the main texture scale that an observer perceives on a high gloss surface at typical showroom viewing distance (around 1.5 m). It describes whether the orange peel structure appears fine and tight or coarse and large‑scale.

Unit and range

Dimension is expressed in millimetres (mm). Typical values for automotive clear‑coat lie between about 0.5 mm and 8 mm.

  • Lower D values correspond to fine, closely spaced orangepeel.
  • Higher D values correspond to coarser, more widely spaced structure.

Measurement conditions

Dimension is available in High Gloss Mode when the surface type is set to C‑Coat and a high‑gloss algorithm such as CC‑TAMS‑STD is selected. It is derived from the measured surface texture spectrum used for waviness and other appearance parameters, so it does not require any extra measurement steps beyond a normal clear‑coat reading on a clean, defect‑free area.

Visual meaning at showroom distance

At around 1.5 m, Dimension describes the characteristic spacing of the surface waves that form the orange peel pattern:

  • Small D (fine structure): The surface shows a tight, fine orange peel.
  • Large D (coarse structure): The surface shows broad, large‑scale waves.

Because it reflects the dominant spatial scale rather than just the amplitude, Dimension helps explain why two panels with similar waviness can still look different to the eye.

Relationship to other TAMS parameters and indices

Dimension works alongside the other High Gloss parameters:

  • With Waviness (W) it separates “how strong” the orange peel is (W) from “how large” the texture cells are (D).
  • It supports interpretation of Harmony (H) by indicating whether a panel‑to‑panel mismatch is mainly due to differences in texture scale. In the latest SMS‑based Harmony algorithm, D is retained as a diagnostic value even though it is no longer used directly in the H calculation.
  • Together with Sharpness (S) and Contrast (C), it helps engineers understand whether perceived appearance issues are dominated by coarse body‑shape variations, finer orange peel, or haze.

Typical interpretation

  • D < 1 mm: Very fine texture.
  • D ≈ 1–4 mm: Shortwave orangepeel dominant in the painted surface.
  • D > 4 mm: Longerwave orangepeel dominates the surface.