Saving Ink and Under Colour Removal (UCR) – Ways to Improve Your Business
Most printers these days have to look into all the options to cut
cost and give them a competitive edge.
Fast make-readies and minimising waste sheets are where the greatest savings can be achieved. Reducing actual ink usage can have a positive effect over time, however it remains that getting a job to colour quickly and accurately has the by far greatest impact to the bottom line.
UCR - how to save ink
By reducing the amount of magenta, cyan, and yellow in image areas exceeding a predetermined (ICC profile controlled) threshold and replacing same with black ink, the total ink densities can be reduced without affecting the visual result of the print. This technique is called UCR (under colour removal). The principle is simple: coloured ink is used up to a certain value, after which black is added in order to improve the contrast of an image, so that the total ink coverage is not exceeded. The depth of colours is thus improved and the total amount of printing ink reduced.
Although the ink saving effect is generally positive, there are also downsides to use UCR. If CMY are removed from a dark picture to a large extent, attention needs to be paid to grey balance.
The UCR therefore should not be a generic approach for all jobs, files or print areas, but has to be used carefully to achieve the benefits without jeopardising the print quality.
What about ISO?
The ISO 12647-2 compliancy does not focus on printed densities, but goes by absolute L*a*b* values. As a result you will not find colour tolerances inside an ISO standard described in terms of their CMYK values.
This means, that a printer could use his own separation set-up (RGB to CMYK conversion), own specific ink sets (as long as they conform to the specifications of the ink standard), substrate, and printing press and in theory still achieve a result that is compliant with the ISO print standard.
The question is what aim has the UCR. Naturally all ICC profiles include UCR, as the mix of CMYK is defined individually by the profile for each device. However, if UCR is increased to a level for saving ink, the profile will need to be handled separate to the non-UCR ones as ink saving UCR cannot be used for every job. The initial set-up and maintenance of two standards (with and without UCR) will result in a lot of effort, time, and money.
The real benefit
The press by nature would have the highest internal cost, which is why the biggest saving potential in print today remains in fast make ready.
The real benefit in using UCR therefore is not saving ink, but to establish a colour environment which is predictable and repeatable and therefore will reduce make ready times. Because all UCR does is applying an ICC profile in the RIP to a job, which requires a colour managed process. Part of a colour managed environment - in fact part of every ICC profile - is to realise UCR for different presses and proofers. The only question is to what extent and with what aim. Colour Management mainly aims for reliable colour control and UCR is just part of this. Saving ink therefore is not necessarily achieved by UCR, but the colour control in general will have a higher benefit to a company.
Heidelberg can offer services and products to achieve an ISO certification. But what is more, if customers want to introduce UCR to save ink, MetaDimension users already have almost all they need to realise this, pivotal to this is activating the correct ICC profile. The need to invest in third party tools is not required.
Find out how to set up your MetaDimension RIP by reading the Tips and Tricks items in this newsletter or contacting your local Heidelberg sales or service representative.
Fast make-readies and minimising waste sheets are where the greatest savings can be achieved. Reducing actual ink usage can have a positive effect over time, however it remains that getting a job to colour quickly and accurately has the by far greatest impact to the bottom line.
UCR - how to save ink
By reducing the amount of magenta, cyan, and yellow in image areas exceeding a predetermined (ICC profile controlled) threshold and replacing same with black ink, the total ink densities can be reduced without affecting the visual result of the print. This technique is called UCR (under colour removal). The principle is simple: coloured ink is used up to a certain value, after which black is added in order to improve the contrast of an image, so that the total ink coverage is not exceeded. The depth of colours is thus improved and the total amount of printing ink reduced.
Although the ink saving effect is generally positive, there are also downsides to use UCR. If CMY are removed from a dark picture to a large extent, attention needs to be paid to grey balance.
The UCR therefore should not be a generic approach for all jobs, files or print areas, but has to be used carefully to achieve the benefits without jeopardising the print quality.
What about ISO?
The ISO 12647-2 compliancy does not focus on printed densities, but goes by absolute L*a*b* values. As a result you will not find colour tolerances inside an ISO standard described in terms of their CMYK values.
This means, that a printer could use his own separation set-up (RGB to CMYK conversion), own specific ink sets (as long as they conform to the specifications of the ink standard), substrate, and printing press and in theory still achieve a result that is compliant with the ISO print standard.
The question is what aim has the UCR. Naturally all ICC profiles include UCR, as the mix of CMYK is defined individually by the profile for each device. However, if UCR is increased to a level for saving ink, the profile will need to be handled separate to the non-UCR ones as ink saving UCR cannot be used for every job. The initial set-up and maintenance of two standards (with and without UCR) will result in a lot of effort, time, and money.
The real benefit
The press by nature would have the highest internal cost, which is why the biggest saving potential in print today remains in fast make ready.
The real benefit in using UCR therefore is not saving ink, but to establish a colour environment which is predictable and repeatable and therefore will reduce make ready times. Because all UCR does is applying an ICC profile in the RIP to a job, which requires a colour managed process. Part of a colour managed environment - in fact part of every ICC profile - is to realise UCR for different presses and proofers. The only question is to what extent and with what aim. Colour Management mainly aims for reliable colour control and UCR is just part of this. Saving ink therefore is not necessarily achieved by UCR, but the colour control in general will have a higher benefit to a company.
Heidelberg can offer services and products to achieve an ISO certification. But what is more, if customers want to introduce UCR to save ink, MetaDimension users already have almost all they need to realise this, pivotal to this is activating the correct ICC profile. The need to invest in third party tools is not required.
Find out how to set up your MetaDimension RIP by reading the Tips and Tricks items in this newsletter or contacting your local Heidelberg sales or service representative.
