What is ISO/TS 21139‑21 about?
ISO/TS 21139‑21 describes the test method for light stability and ozone stability for commercial prints, which are displayed in indoor bright places in or near to windows, especially in display windows with air conditioning. ISO/TS 21139‑21 also provides guidelines for data analysis.
ISO/TS 21139‑21 is applicable to the various product classes of “commercial prints” that, following the terminology of ISO/TR 19300, include commercial production prints (flyers, brochures), transactional and stationery prints, signage, newspapers and periodical prints, book printing as well as packaging printing. These commercial prints often contain combinations of text, pictorial images and/or artwork. Prints for non-commercial use, including prints used and displayed in consumer home environments and prints exhibited or stored in a museum context, are outside the scope of ISO/TS 21139‑21.
ISO/TS 21139‑21 is applicable to both analogue and digitally printed matter. Methods and principles apply to both, colour and monochrome prints.
Who is ISO/TS 21139‑21 for?
ISO/TS 21139‑21 on permanence and durability of commercial prints is useful for:
- Printing equipment manufacturers and suppliers
- Printing production personnel
- Printing professionals, including auditors, consultants, etc.
- Print buyers and purchasers
Why should you use ISO/TS 21139‑21?
In commercial application of colour prints, displaying the prints under ambient light or artificial illumination is one of the typical use cases. These prints may fade or otherwise change in appearance due to various environmental stresses, such as light, heat, humidity, pollutant gas, biological weathering, and the combination of these factors. One of the most critical degradations is light fading caused by a bright light which includes some UV components.
A test method for light stability of prints by simulating daylight through window glass directly falling on a print displayed in a window is described in ISO 18937. The test method described in ISO 18937 has broader application (for example covers a broad range of temperatures) than is required for ISO/TS 21139‑21 and so requires some modification. A test method for ozone stability is described in ISO 18941.
In addition, ISO 18937 and ISO 18941 focus on the test method itself, and do not cover translation of test results into performance in specific use profile which is one of the aims of ISO/TS 21139‑21.
