SWOP (Specifications for Web Offset Lithography)


Please be advised that SWOP & GRACoL have adopted new Specifications to comply with ISO standards in lighting.  Prepress Professionals, Advertisers, Publishers, Printers, and Photographers who evaluate color under standardized D50 lighting in the Graphic Arts Industry are affected by this change.

When is this going into affect?

SWOP & GRACoL have already made the change to include the updated ISO 3664:2009 standard.  The lighting manufacturers GTI and JUST Normlicht are now manufacturing their light bulbs to comply to the updated ISO standard.

When do I need to change by?

As an industry we all need to do our part to make the switch together.  Therefore SWOP has made the mandate that everyone is using updated D50 light bulbs by January 1st, 2012.

What do I need to do to be compliant with the new ISO Standard?

GTI and JUST Normlicht no longer manufacturer, stock or ship bulbs  conforming to the outdated standard. If you are using expired light bulbs in your viewing booths, simply purchase new ones from your normal suppliers and be sure to ask for bulbs that comply with the ISO 3664:2009 Standard.

Note:  In some cases the luminaire lens may block enough UV energy as to require replacement in order to comply with the new standard – please check with the manufacturer of your viewing system to verify this.  

We recently bought new bulbs, how do I know if they are for the old standard or the new one?

You can tell by looking at the label on the bulbs or packaging they come in. 

GTI: Look for the three-character code printed on the bulbs.  The important thing you want is that the LAST character of the code is an “E”. The old standard had an “X”. If you do not have an “E” then you need to purchase new bulbs.  Source:  www.gtilite.com

JUST Normlicht: Look for the imprinted ISO standard ISO 3664:2009. If this is not printed on the bulbs then you must purchase new bulbs.  Source:  www.just.de/us

What else do I need to do?

Inform your clients, vendors and customers about using the new ISO compliant bulbs. If someone’s light booth is different from yours, there is a good chance that color evaluation may be different. Be sure all light booths are using ISO 3664:2009 D50 light bulbs .

Below are example images of the new bulbs.



About SWOP

Over the last thirty years the Specifications for Web Offset Publications (SWOP) has become a major factor in the success of the Publication Printing Industry in the United States. This has been a result of a combination of attainable goals, dedicated people driving the process and an industry willing to improve itself. The resulting recommended specifications are for the use of all those involved in the production of publications - including the advertiser, publisher, printer, advertising agency and prepress service supplier.

To participate join the GRACoL-SWOP Working Group.