Introduction

The Digital Data Distribution for Australian Publications (3DAP) committee is a committee endorsed by the Magazine Publishers Association and formed with two objectives: -

1. To develop guidelines for a suitable file format for digital advertising delivery for Australian magazines
2. To develop guidelines for digital proofing of this file format acceptable to stakeholders in the approval process i.e. Advertiser’s, Pre-press suppliers, Magazine Publishers and Printer’s

These two objectives have a common constraint; the file format and proofs must deliver a predictable, stable result for the advertising community. Therefore, proofing needs to be at least as predictable as the current analogue proofing. The file format must deliver as predictable a workflow as film has in the past.

3DAP does not claim that a compliant file and proof will eliminate all disputes between the stakeholders in regard to printed “quality”, content and timeliness.

The standard proofing objective is a multifaceted challenge as unlike a file standard many types of digital proofs are available and used in the marketplace today. Digital proofs like their predecessors the analogue proof (film based proofing) do not have a standard CMYK colour space to conform to in Australia. However, certain proprietary brands have evolved to become de facto industry standards for what is termed “contract colour”.

Contract colour proofs are proofs acceptable as a true guide to the final printed product, by all the stakeholders in the approval process.

There is no standard CMYK colour space and digital proofs are subject to change in colour by a user. The committee decided to pick one analogue proof to serve as the contract colour proof standard and match all digital proofs to this proof.

Eurosprint Cromalin analogue proof is the accepted target proof. The committee chose this proof, as it is the de facto analogue proof used for magazine advertising in Australia. This meant that the existing separations did not need to be altered to suit a new digital colour space. This task the committee may deal with in the future - to develop a digital proof standard which is closer to print conditions over a variety of substrates.

The committee developed a set of target images, which are proofed using a standard Cromalin and then compared to the digital proof produced from the same file as the analogue film. Spectrophotometry is used as an aid to proof checking – but the final approval is determined by viewing the proofs under controlled conditions. The lighting conditions conform to the ANSI standard and we have adopted GTI light sources as the standard vendor.

Digital proofs are variable which are both strength and a weakness. Variation can be caused by the limitations of the device and or inks etc but the variation that we are concerned with is the user definable variety. The variables change from vendor to vendor but in general the user can change, proofing substrate, ink or dye colours, base line calibration on the device and most importantly the colour-profiling table loaded into the device. To document standards and keep them up to date for all these variables is indeed a challenge, especially when the number of vendors in the market multiplies the variables.

The answer was to seek the help of the proof vendors who want 3DAP approval. The request to them is that they administer a QC system to ensure standard proofs are produced.

3DAP Control Strip

In order to verify the accuracy of data transfer and/or interpretation, each proof must have the following 3DAP endorsed Control Strip displayed beside the advertising material.

This wedge is only available from 3DAP approved, proofing systems suppliers and must show:

• The proof originators company name /logo (in the example above it is Sinnott Bros).
• The Proofing device used (in the example above it is IRIS)
  

The control strip normally is placed beside the advertising page prior to proofing as an element- ensuring that any 3DAP profile is applied to the control strip.

Proof viewing conditions

Correct viewing conditions are essential when viewing proofs. For accurate colour and tonal value perception, International Standards state that lighting of 5000K (ANSI standards PH 2.30-89) should be used for viewing and have a colour-rendering index (intensity) in the high 90s.

The viewing area should be glare-free neutral Grey. The influence and effect of daylight when viewing material can also dramatically alter how colour appears.

The committee is aware that a new International viewing standard has been adopted, the ISO 3664 - 2000.

We have been informed by suppliers that they will gradually conform to this new standard, but are also advised that the variation between the ANSI PH 2.30 - 89 and the ISO 3664 - 2000 is minimal, and in fact, within an acceptable tolerance level.