Press sheet certification

Reading press sheet certification (PressSign)

Our print suppliers who use PressSign software (for example Clays UK), have the ability to produce certification documents to prove the colour accuracy of CMYK inks on printed sheets for wet proofs and press sheets. PressSign software empowers the printer to accurately read the colour, and helps the press minders to make improved colour adjustments on press. They can then provide a certification document to prove how accurate the printed sheet was using a simple percentage score along with analysis of the readings including dot gain and colour balance.

A score of 100% means the printer has printed the sheet perfectly within the tolerances allowed for the ISO12647-2 which FOGRA39 and FOGRA47 are based upon.

A score below 100% is not unusual; +90% is very good, +80% in most cases is ok, with measurements saved in the software and all scores reviewed regularly, fed back to suppliers and managers.

A score below 80% shows a serious difference between the colours set in our files and verified proofs, and the final printed result. If you have a score below 80% please inform your manager and Tom Morse – Technical Prepress Manager for DK.

Instructions for measuring colour accuracy using PressSIGN

PressSIGN Overview

Penguin and DK have access to PressSign software. It allows us to accurately read the colour from the sample printed sheets (sometimes called running sheets) supplied from our print suppliers that cannot provide PressSign certification documents. This information can then be stored in the applications database and also made into PDF reports.

The press sheets to be measured, need to have been printed and supplied with the PressSIGN colour bar on in order for us to be able to read them using PressSIGN. Please watch the short video below how to read the bar and make a report.

To make a PressSIGN Colourbar

In order to get the best results from PressSIGN we ask suppliers to tell us two numbers:

• The width of each ink zone sometimes called ‘track’
• The maximum print area of sheets they will print

With these two numbers we can export a colourbar from PressSIGN.

In the menubar choose FILE > EXPORT > COLOUR BAR

Enter the two supplied numbers in Ink Zone Width and Full Bar Length fields. For all other options, choose the options shown in this image and click ‘Generate’ to save a PDF or EPS graphic which can be emailed to the printer.

When sending a colourbar to a printer include this line of information in the email.

Please note: If you need to trim the colour bar for a smaller sheet or print area please trim each left and right side equally, not from one side only.