# ASTM D4414

Source: https://coatmentor.com/standards/astm-d4414/ · Updated 2026-10-14

Measuring wet film thickness with notch (comb) gauges.

**Publisher**: ASTM International

**Area**: Application and film thickness

A notch gauge is pressed square into the wet film straight after application. The wet film is between the last notch that touched paint and the first one that stayed clean.

## Two forms of gauge

- **Procedure A:** a straight notched plate, for about 3 to 2,000 µm.
- **Procedure B:** a circular gauge rolled through the film, for about 25 to 2,500 µm.

## How far to trust it

D4414 itself calls notch gauges neither accurate nor sensitive. A notch reading guides the painter while the film can still be corrected. The specification accepts the dry film, measured later with a DFT gauge.

From the volume solids, WFT = DFT × 100 ÷ VS, with a correction when thinner is added. ISO 2808 lists the same tools as methods 1A (comb) and 1B (wheel).

**Use it:** [WFT ↔ DFT calculator](https://coatmentor.com/calculators/wft-dft/)

**4** practice items in the members area mention ASTM D4414 (CIP 1: 3 · CIP 2: 1).

## Related

- **Concepts:** [Volume solids, wet film and dry film](https://coatmentor.com/learn/volume-solids/)
- **Standards:** [ISO 2808](https://coatmentor.com/standards/iso-2808/) · [ASTM D7091](https://coatmentor.com/standards/astm-d7091/)
- **Defects:** [Mud cracking](https://coatmentor.com/defects/mud-cracking/) · [Runs and sags](https://coatmentor.com/defects/runs-and-sags/)

## About this page

This page describes the subject of ASTM D4414 in our own words; it does not reproduce the standard. For the full text, buy the current edition from ASTM International. Checked on 2026-10-14; errors go in the [corrections log](https://coatmentor.com/method/). CoatMentor is an independent study aid. It is not affiliated with ISO, AMPP, SSPC, NACE International, ASTM or FROSIO.