Overview
ISO 2834-2:2022 - Graphic technology - Laboratory preparation of test prints - Part 2: Liquid printing inks - specifies a laboratory test method for producing reproducible test prints using liquid printing inks (water‑based, solvent‑based, or radiation‑cured) as used in flexography and gravure. The standard is intended for making homogeneous, reproducible ink films for reflection‑based measurements (e.g., colorimetry, optical density), light‑fastness testing, and mechanical or chemical resistance tests. It explicitly excludes inks for inkjet printing.
Key topics and technical requirements
- Scope of inks and processes: Covers liquid printing inks for flexo and gravure; not applicable to inkjet or paste/screen inks (see other parts of ISO 2834 series).
- Laboratory proofer requirements: A proofer must provide automated, repeatable control of ink transfer (adjustable printing speed, pressure/impression) and produce a uniform printed ink film at the required thickness.
- Printing formes and anilox/engraving:
- Gravure formes can be engraved, laser‑engraved or chemically etched and should include solid 100% tone patches (≥ 1 600 mm²).
- Flexographic formes are relief type; the anilox roller and doctoring device must be specified.
- Ink transfer characterization: For each proofer/forme/ink/substrate setting, the ink transfer shall be determined (see clause 4.4.4) and recorded; parties must agree on methods and settings to ensure comparability.
- Materials and conditions: Specifies choice of ink, substrate, drying, climatic conditions (ISO 187 referenced), and methods to determine ink film coverage and thickness (ISO 13655 referenced for spectral measurement).
- Reporting and traceability: Test reports should document apparatus, materials, process settings, ink transfer values and any conditioning so results can be reproduced between laboratories.
- Representative values: The standard notes typical dried gravure ink film thickness (~2.25 µm ± 1 µm) as industry guidance.
Applications and users
ISO 2834-2:2022 is practical for:
- Ink manufacturers validating color, density and resistance properties of liquid inks.
- Print laboratories and QC teams producing standardized proof prints for colorimetric and durability testing.
- Packaging and label converters assessing ink/substrate compatibility and light/chemical resistance.
- Standardization and testing bodies ensuring inter‑laboratory reproducibility of optical measurements.
Benefits include improved repeatability of test prints, comparable color/optical data across labs, and a clear framework for documenting ink transfer and process parameters.
Related standards
- ISO 2834-1 (paste inks / offset proofing)
- ISO 2834-3 (screen inks)
- ISO 187 (conditioning and atmosphere for paper/board)
- ISO 13655 (spectral measurement and colorimetric computation)
Keywords: ISO 2834-2:2022, liquid printing inks, laboratory proofer, flexography, gravure, ink transfer, test prints, colorimetry, optical density, printing inks testing.