SIDs and target Lab values

[gordo]

Glenn Andrews owner at Color Clarity a color management and process control consulting service has publicly stated that: "The reason that the widespread tradition of running M .1 density above C is no longer valid and should be discarded is because that will rarely get you primary Lab values. With most ink sets, C and M require approximately equal densities, or C slightly above M in density to achieve proper Lab values for primary targets."

Have any of you found that to be true? I.e. that you should run at approximately Black 1.60, Cyan 1.40-1.50, Magenta 1.40, and Yellow 1.00 to hit the required primary Lab targets (assuming a KCMY ink sequence)?

best, gordo

 

[Deleted member 16349]

Glenn Andrews owner at Color Clarity a color management and process control consulting service has publicly stated that: "The reason that the widespread tradition of running M .1 density above C is no longer valid and should be discarded is because that will rarely get you primary Lab values. With most ink sets, C and M require approximately equal densities, or C slightly above M in density to achieve proper Lab values for primary targets."

Have any of you found that to be true? I.e. that you should run at approximately Black 1.60, Cyan 1.40-1.50, Magenta 1.40, and Yellow 1.00 to hit the required primary Lab targets (assuming a KCMY ink sequence)?

best, gordo

Responses from printers would be interesting.

I would think it depends on the particular inks and paper used. Their strength and the wet trap values on the press. I doubt that different CMYK ink sets are similar enough to be able to make such a statement.

 

[tmiller_iluvprinting]

We have found that in order to 'hit' the blue(magenta-cyan overprint) ISO Lab target numbers it is still necessary to run the magenta slightly heavier than the cyan. We have found that if we run the cyan heavier than the magenta not only the Lab values suffer, but the magenta-cyan trap values suffer also(58%-62%.) Most of our standard density work is run at K 1.70, C 1.40-1.45, M 1.45-1.50,
Y .95-1.00, this is work that the customer does not require an Epson proof on.
Regards,
Todd

 

[gordo]

We have found that in order to 'hit' the blue(magenta-cyan overprint) ISO Lab target numbers it is still necessary to run the magenta slightly heavier than the cyan. We have found that if we run the cyan heavier than the magenta not only the Lab values suffer, but the magenta-cyan trap values suffer also(58%-62%.) Most of our standard density work is run at K 1.70, C 1.40-1.45, M 1.45-1.50,
Y .95-1.00, this is work that the customer does not require an Epson proof on.
Regards,
Todd

Thanks. That's been my experience also. Can anyone else pipe in with their experience?

Thanks, Gordo

 

[kansasquaker]

Glenn Andrews owner at Color Clarity a color management and process control consulting service has publicly stated that: "The reason that the widespread tradition of running M .1 density above C is no longer valid and should be discarded is because that will rarely get you primary Lab values. With most ink sets, C and M require approximately equal densities, or C slightly above M in density to achieve proper Lab values for primary targets."

We're running Flint Flora Premium inks on Xpedx Endurance (from UPM). We just did a press profile and our best SIDs were running k-1.68, c-1.37, m-1.3 and y-.96. That put the target lab within 3 dE for all solids as well as overprints. So, that's cyan +.07.

The same was not true when we were running a set from Toyo (sorry can't remember which exactly). There we were running cyan and magenta at very similar densities. However we found a bit of a tradeoff between the hitting the c,m targets and the overprint targets. For example the lab value of blue overprint would suggest lowering m density but lab value of the m by itself would suggest increasing it. We had a similar situation with the red overprint.

 

[BeauchampT]

I am throwing into this a bit late, but....we have found we run between C and M being at similar levels to M being higher (0.1 to 0.05). This is mostly for our MY and CM overprints.

This has held true running Flint, CIC, Hostman, Imex, and Braden-Sutphin.