SIST ISO 20654:2018

Name: SIST ISO 20654:2018 — Graphic technology - Measurement and calculation of spot colour tone value
SKU: SIST ISO 20654:2018
Price: 18000 RUB
Availability: InStock

Graphic technology - Measurement and calculation of spot colour tone value

Название (английский):

SIST ISO 20654:2018

Graphic technology - Measurement and calculation of spot colour tone value

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 10
Дата публикации:: 9 января 2018 г.
ICS:: 17.180.20
Технический комитет:: GRT - Graphical technology

Тип поставки:

Full version18 000 ₽Read online 24h1 200 ₽Read online 72h1 800 ₽

Язык документа:

ruen

Срок поставки:2 раб. дн. (перевод)

Цена:18 000 ₽

Описание (английский):

ISO 20654:2017 defines a metric for assessing intermediate tones of a spot ink. This method for the calculation of Spot Colour Tone Value (SCTV) produces approximately uniform visual spacing of tones between substrate and solid. It can be calculated from spectral reflectance or colorimetric measurements of the solid ink, substrate and one or more patches of intermediate tones to be measured.

Abstract

Похожие стандарты

Стандарты, упомянутые в описании

Overview

ISO 20654:2017 specifies a metric and measurement method for assessing intermediate tones of a spot colour ink. The standard defines the Spot Colour Tone Value (SCTV), a substrate‑relative metric that maps tones from the unprinted substrate (0 %) to the spot ink solid (100 %) and produces approximately uniform visual spacing of halftones. SCTV can be calculated from either spectral reflectance (or transmittance for back-lit media) or from CIELAB colorimetric measurements.

Key topics and requirements

Definition of SCTV: A normalized metric (0–100 %) based on three value components derived from tristimulus data (X, Y, Z) using a compression function analogous to CIE L*.

Measurement inputs: Spectral reflectance (or transmittance) of the substrate, the spot ink solid, and one or more intermediate tone patches; selected illuminant (normally D50 for graphic arts).

Calculation routes:

From spectral reflectance: compute X, Y, Z following ISO 13655, convert to the Vx, Vy, Vz components, then apply the SCTV formula.
From CIELAB: measure L*, a*, b* (D50/2° recommended) and convert to the V components using the specified algebraic formulae; these are equivalent to the spectral route when CIEXYZ and CIELAB are consistent with ISO 13655.

Communication: The standard recommends using CxF/X-4 (ISO 17972-4) to exchange spot ink characterisation data where possible.

Scope notes: Applicable to non‑process (spot) inks; note on use for back-lit materials (use transmittance).

Applications and who uses it

Ensures consistent halftone appearance for spot colours across prepress, printing suppliers and substrates.

Practical uses:

Brand and packaging colour control where spot inks (brand colours) are critical.
Quality control and production acceptance criteria for halftone ramps and gradations.
Color management, prepress proofing, and specification of spot ink tone values in tender/spec documents.

Typical users:

Print production managers, packaging converters and brand owners.
Color technologists, spectrophotometer manufacturers, and color labs.
Prepress and ICC/profile specialists who manage spot colour workflows.

Related standards

ISO 13655 - Spectral measurement and colorimetric computation for graphic arts (used for converting reflectance to CIEXYZ).

ISO 17972-4 (CxF/X-4) - Spot colour characterisation data format (recommended for communicating spot ink data).

ISO 12647 (context) - general graphic technology/process colour definitions.

Using ISO 20654 improves reproducibility and perceptual uniformity of spot colour tones, helping suppliers and brand owners achieve consistent printed appearance across workflows and substrates. Keywords: ISO 20654, SCTV, spot colour tone value, spot color, spectral reflectance, CIELAB, CxF/X-4, graphic technology.

SIST ISO 20654:2018

Abstract

Похожие стандарты

Overview

Key topics and requirements

Applications and who uses it

Related standards

Технические детали

ISO 20654:2017

Graphic technology — Measurement and calculation of spot colour tone value

BS ISO 13655:2017

Graphic technology. Spectral measurement and colorimetric computation for graphic arts images.

ISO 17972-4:2015

Graphic technology — Colour data exchange format (CxF/X) — Part 4: Spot colour characterisation data (CxF/X-4)

BS ISO 12647-8:2021

Graphic technology. Process control for the production of half-tone colour separations, proof and production…