Standard ink densities?

[Gregg]

Just received a third party process swatch book. In the book it lists the densities that the job was run at. They are:

K: 1.90
C: 1.45
M: 1.50
Y: 0.95

Are these standard numbers? If not, what are standard numbers, or is this simply to vague of a question?

To be honest I know little on this topic.

[disbellj]

If you look at page 21, Section 6.2, of "G7_how-to_v6[final]" freely downoadable from www.gracol.org, although solids are to be run to Lab aim values, approximate Status T densities are listed:
C 1.45 +/- 0.10
M 1.45 +/- 0.10
Y 1.0 +/- 0.07
K 1.7 + 0.2 - 0.05

So the densities you listed are within that tolerance. Next would be to check TVI, but since TVI is obtained from colorimetry in GRACoL2006_Coated1, then the TVI values are gonna be different than TVI obtained from densitometry. To get TVI values obtained from densitometry, you'll need to purchase ISO 12647-2. Note: Solids for GRACoL2006_Coated1 are the same as ISO 12647-2 solid Lab values.

Don

[Gregg]

Thanks, Don.

I must admit, alot of what you mention is over my head. I have no idea what TVI is, but I am in the process of printing that Gracol doc you mention and will have a read.

Thanks again.

[wallsmith]

TVI is the dot gain. It is irrelevant for measuring total ink density on a solid swatch. The numbers from Gracol are the results from their given ink and paper. I found that all of these recommended densities worked except cyan which was closer at a density of 138. This was based on Kohl-Madden Spectrum series ink on Sterling Ultra stock. The way for a printer to determine the printing density is run a variety of densities and take lab readings using a densitometer. The density that comes closest to the target is what you should run to. This will vary by ink and paper combination.

If you are refering to the Pantone swatch guides that list the densities that the book was created with, I would be skeptical. Take an actual reading of the book with your densitometer and will find that these numbers will vary greatly. Of the course the designer that is thinking the swatch book is blessed by God himself doesn't understand all of this.

[ian]

The values you have mentioned are what we use for coated paper.
Does anyone have the values for uncoated paper??
We use
C-110
M-110
Y-95
K-130

[carlosiglesias]

The standard ISO 12647-2 does not define valuables of density. Only Lab. defines values
It is necessary to accomplish a test of inky to define correct the values of density at each workshop. These varied in terms of ink, the paper, etc ...

Pardon for my very bad English.

[larrysison]

Hi Gregg,

IMHO, your standard densities can be can be of any value. As long as it gives you a color gamut that is big (hopefully bigger than ISO 12647-2) and that it is gray balanced, and that your CMYK solids are within Delta E of 5.

Once you get your Delta E within the limit, measure now your solids and check your density value per color (CMYK).

These new values are now your personalized standard densities for that particular set of ink and paper. To be on the safe side, you may want to cross check whether the same density values can also be applied when you change any of your materials (ink, paper weight, etc.).

Hope this helps.

Larry

[dwanehollands]

> {quote:title=ian wrote:}{quote}
> The values you have mentioned are what we use for coated paper.
> Does anyone have the values for uncoated paper??
> We use
> C-110
> M-110
> Y-95
> K-130

Hi Ian,

Sorry to but in, but do you have values for running Matt/Satin stocks?

cheers!

dwane

[sugeng]

I am agree with Larry, the choice of standard density and tolernce very costumized depend on the quality of ink (purity, hue error, and rich gamut). Ink level has a density absolute, we put optimum level where no set-off, printthrough. And when it's printed on stock has a specific absorp, we called ink dry back. If we refer on ISO 12647-2, we must set ink, paper, and ink level as certain setting, make sure all combination standard. But dont forget think about TVI, because optical dotgain from penetrate oil was a problem too.

[kheskins]

we use on uncoated
C-90
M-90
Y-90
K-125

coated
C-125
M-125
Y-110
K-160