ISO 12647-3:2013

Overview

ISO 12647-3:2013 - "Graphic technology - Process control for the production of half‑tone colour separations, proofs and production prints - Part 3: Coldset offset lithography on newsprint" - defines process parameters, measurement methods and tolerances for producing single‑ and four‑colour newspaper printing using coldset offset. Its intent is to improve communication between printers, publishers and advertisers, enable predictable print results, and provide objective quality evaluation criteria that raise newspaper competitiveness.

Key topics and technical requirements

• Scope and purpose: Parameters cover the full workflow - colour separation, making printing forms, OK‑print/proofs and production printing - specifically for coldset offset on newsprint (also applicable by analogy to direct imaging and non‑periodic screens).
• Data and file formats: Digital files should be CMYK (or three components) and exchanged as PDF/X (ISO 15930). ICC output profiles and the intended printing condition should be supplied; use ISO/TS 10128 methods if adjustment is required.
• Printing form and prepress:
  • Platesetter resolution: minimum 393 cm⁻¹, recommended 500 cm⁻¹.
  • Tone value deviation across a printing form: ≤ ±1.5 %.
• Screening:
  • Periodic screen frequency: 40–54 cm⁻¹ (≈100–140 lpi); uniform ruling across a product is recommended.
  • Non‑periodic (stochastic) dot size: 40 µm ± 10 µm.
  • Screen angles / dot shape: recommendations for nominal angle separations (e.g., 30° between C/M/K, yellow offset by 15°) and elliptical dot shapes for periodic screens.
• Tone value and colour handling:
  • Tone value sum (TVS): should not exceed 220 %, shall not exceed 240 %; when near limits, black tone value should be ≥ 90 %.
  • Grey reproduction and grey balance calculations are specified (accounting for the natural colouration of newsprint).
  • Normative ΔE* tolerances for primary and secondary colours and a general tone value increase curve are included.
• Proofing and measurement: Digital proofs or displays shall not be used as measurement references; an OK‑print, press proof or stored OK‑print is required as the reference. Spectral and colorimetric computation follow related standards (e.g., ISO 13655).

Practical applications - who uses this standard

• Newspaper printers and press operators: implement process control targets, screening and TVS limits to stabilize runs.
• Prepress technicians and colour managers: prepare separations, ICC profiles and PDF/X files compliant with the defined printing condition.
• Publishers, advertisers and print buyers: use tolerances and OK‑print definitions to set expectations, approve proofs and evaluate quality.
• Equipment suppliers and plate makers: align imaging, screening and plate resolution to meet ISO targets.

Related standards

• ISO 12647‑1: Parameters and measurement methods
• ISO 2846‑2: Colour and transparency of printing ink sets - coldset offset
• ISO/TS 10128: Data adjustment methods
• ISO 15930 (PDF/X) and ISO 13655 (spectral measurement)

ISO 12647-3:2013 is essential for anyone managing colour fidelity and predictable production results in coldset offset newspaper printing. Keywords: ISO 12647-3:2013, coldset offset lithography on newsprint, process control, colour separation, grey balance, tone value sum, PDF/X, ICC profile, newspaper printing standards.