Tuesday January 16, 2018

Back to black: how to print ‘deep’ or ‘rich black’

Topics: PitStop Pro

Using black ink for offset printing can be a tricky business. We’ve all been there, scratching our heads when we see a supposedly jet black area turn out grayish, greenish or even bluish in print. Fortunately, graphic designers and printers have a few tricks up their sleeves to solve this common printing problem and create what is known in the printing industry as rich black or deep black.

There’s black and then there’s black

Printing rich black can be done in several ways. Some printers stick to a recipe that uses 100 percent black, 60 percent cyan, 40 percent magenta and 40 percent yellow. Others choose to use 100 percent black with 40 percent magenta, 40 percent yellow and throw in 40 percent cyan into the mix. Some printers, however, choose to omit yellow altogether as it sometimes causes ink piling (buildup). When attempting to print rich black, the substrate needs to be taken into account as well. Paper that has, for instance, a slightly bluish undertone needs little less cyan added.

Avoiding excess ink coverage

If you’re wondering why printers don’t use 100 percent of each color to achieve rich black, maximum ink coverage is your answer. As a rule of thumb, ink percentages for offset/commercial printing should never exceed 240 when added up – unless you want to risk causing problems on the printing press, long drying times and muddy images.

Printing small black objects

It’s best to refrain from using rich black for thin lines or areas that are less than 5 mm wide as this is known to cause registration issues.

About to print rich black?

If you want to make absolutely sure printing rich black won’t cause excess ink coverage issues, use a preflighting tool – it will take care of all of your worries and automatically reduces the ink values to your own standards while keeping the black nicely deep and rich.

See for yourself now – and download a free 30 day trial of PitStop!

Try PitStop for free

 

About Andrew Bailes-Collins

PitStop Pro 2018

Andrew Bailes-Collins is Senior Product Manager at Enfocus.

He graduated from what is now the London College of Communications and went on to serve an apprenticeship as a compositor. He has worked for a number of vendors in the printing and publishing sector, including Scangraphic, Apple and DuPont/Crosfield.

Andrew has been Prepress Manager for several high-quality printing companies in London, managing the change from conventional production techniques to digital. An early adopter of computer-to-plate and PDF workflow, Andrew then worked at OneVision Software for ten years. Initially based in the UK, before rising through the company to become Head of Product Management Europe at their head office near Munich in Germany.

Andrew joined Enfocus and moved to Belgium in 2011 and is the Senior Product Manager responsible for the PitStop family of products. He is also the Technical Officer for the Ghent Workgroup and Co-Chair of the GWG specifications sub-committee.

Read more about:

Sign in or create an Enfocus ID to post comments

Comments

For offset printing, the limit of 240% is not true. This value is for newspaper printing. Offset can very well handle 300% (more when using UV drying). In my experience, rich black can already be achieved using 40/1/1/100 (the 1% of M and Y is added to make sure the object knocks out all other M and Y values underneath if the objects to be set to overprint)
Sign in or create an Enfocus ID to post comments