Pre-press is like good music
Hemanshu Desai of Venus Infotech, draws out comparison between producing good music to good pre-press practices.
30 Sep 2016 | By PrintWeek India
What is colour management?
According to me, it is reproduction of accurate colours, predictably and consistently. It is not a tool available off-the-shelf but a path that needs to be created from printer to designer and they walk on them always.
For me prepress and colour management are like good music, hence the comparison below to help ensure you follow the best practices to achieve your desired results.
Make sure the files are made with the correct working space (colour settings) in the pagemaking software.
If you want to listen to rock band, do you play classical?
In printing also it is important that you decide and use the working space for colours that you wish to achieve. Printing works in CMYK and spot colours depending on the kind of printing, so set it accordingly.
The colour setting must be synchronised such that all software (photoshop, AI, ID etc) have the same colour setting.
Like synchronising all instruments produces great music, synchronisation is must in all the applications that you use.
Once you decide whether you wish to work in CMYK or ‘CMYK+Spot’, you need to decide on the target profile. This could be international standard of FOGRA or GraCol or even your own target profile. This has to be set across all the applications that you use towards making the design.
Otherwise colours would change when data is used across several applications.
Check and maintain the ambient light in the prepress / area of colour correction.
Listening to music needs silent ambience (at least very low disturbing external noise).
Most of us depend on monitors- Thanks to WYSWUG concept but we need to set them as well. Monitor calibration is amustand controlled ambience lighting is also must-do. If your room is too bright during the day and too dark at other times, judgment of colours will vary.
Use monitors that be calibrated as per the ISO standards and calibrate regularly.
Again, what kind ofmusic do you want to listen to? Set music system accordingly.
Decide which standard you want to follow? If it is ISO, set monitor accordingly. Monitors tend to change colours depending on the type and make often because of the heat that it produces - one has to calibrate monitors either weekly or fortnightly.
Proof must be taken on a calibrated printer on certified proofing paper.
Ultimately, listening to music confirms the kind of music you wanted to listen. If it is not of your type change it.
Hard copy proof on calibrated system and on certified media is essential. This is an accurate representation of theprint that you expect from your printing press. You cannot compromise on this using any media and any ink. At times, people shy in investing proofing software, I don't know why.
What is the use of using Bose speakers with Ahuja amplifier?
Digital proofer must be regularly calibrated such that the values are within the ISO12647-7 tolerance.
When you doubt quality of music, you check and correct the setting.
Proofing system also needs such attention. However, depending on proofing solution the calibration may not benecessary all the time. If one is checking proofs by ‘Certified Proof’ application, it will immediately reportthe variation that has come up in the proofing system and thus tell you to re-calibrate if need be.
Proofs must be certified with the media wedge.
Authenticity of the music is must.
Proofs also must be certified, always so that if there is any deviation, you will be alerted. Please realise that we depend on proofs for final prints and if wrong proof is approved, wewill print wrong on press.
Metameric strips (light indicators) to be used to understand the lighting condition of the press.
We judge the music by listening to sound coming out of speakers.
In the same way, we judge the prints by seeing it. The light conditions has a say on the image we see. Thus, it is essential that we understand, measure and maintain the lighting conditions. Metameric strips is one of the easy tool for checking lighting condition.
Check and maintain the pH, conductivity and the temperature of the fountain solution.
Nice melody depends on the condition of all the music playing components.
However small they are, they are important.
These are the small but significant external factors that can affect the printing. Hence very essential to maintain the same.
Verify the paper and ink Lab as per ISO 12647
Original music or remix? The basic ingredients of the original music cannot be replaced to produce same music.
What is print? Ink on paper. If either of these have variation, the colours are going to be affected. ISO or any other standard, one has to keep monitoring both.
Check the blanket to the bearer height and maintain the same as per the manufacturer.
Maintaining impedance of amplifier and speakers as per manufacturer is essential else either amplifier or speakers will be destroyed.
It is important to follows the guidelines given by the manufacturer to produce the desired results.
Music comparisons aside, there are a few more relevant pointers that all of us need to remember.
Regularly check the quality of alcohol used with aerometer.
Again a small but significant factor that effects the print.
Always tight the blankets with the correct torque using a torque wrench.
‘DOT’ gain plays vital role in colour printing. The blanket plays important role here. Uneven pressure will produceuneven print result. Use torque wrench to make sure that the press is even across the width of roller.
Check and maintain the roller setting regularly.
This again effect the ‘DOT’ gain and hence checking and maintaining is must.
Maintain the viewing conditions of the press console as per the standards.
As said earlier, ambience light plays a vital role in judgment of colours.
Print to CIE Lab target values as prescribed by ISO12647 and compare to ISO for solid colour, TVI, and mid-tone spread.
Follow standard. This helps you to achieve print results as predicted and consistently.
Densitometer must be set to ‘Status E’ and always do white calibration, reference white paper when measuring density and absolute white when measuring lab.
All measuring device refers to a base standard. Then the colours are measured and calculated on base standard.
Hence white standard as provided by instrument manufacturing and measuring paper white becomes essential.
Care to be taken for the backing sheet (white backing or black backing) when measuring with the densitometer.
Use the backing sheet provided by the manufacturer. Whether to use white or black will depend on the standard you choose.
Maintain a standard operating procedure (SOP) for all.
What is the fun if SOP is set and not followed? It is like buying a great music system and then playing music through mobile phone.