QTR-Quadtone RIP

(I'm resending with the correct subject - sorry)


Hi Roy,

Here is the data file that I used to make the ICC profile:

Gray      Lab_L

0.00      97

5.00      96

10.00    91

15.00    85

20.00    79

25.00    73

30.00    68

35.00    62

40.00    58

45.00    53

50.00    49

55.00    46

60.00    42

65.00    39

70.00    35

75.00    31

80.00    28

85.00    26

90.00    22

95.00    19

100.00 15

I employed the profile in the Photoshop Print with Preview using 
relative colormetric intent. I tried it both with the BPC on and off.

At first I didn't notice the black was not full black until I looked at 
the black patch of the grayscale next to the black border (the black 
border does not go through the ICC profile and always is sent as 
100%black) and noticed that the black patch was not as dark as the 
border. So it seems that 100% black after going through the ICC profile 
is output as 95% instead. Not obvious at first, but it takes some of 
the punch out of the print.

When the same data are used to Linearize the curve instead, the 
100%black is preserved.

-bruce



> Message: 12
>    Date: Sun, 26 Feb 2006 12:27:13 -0800
>    From: Roy Harrington <roy@...>
> Subject: Re: Re: Create ICC and maximum black in print
>
> Hi Bruce,
>
> Actually for printing there is only one curve and it has 100%K-to-100%K
> builtin
> so I don't think the various intents ought to make a difference.
>
> In soft-proofing however there are many profile conversions happening
> and its
> hard to tell from the PS selections where are the mappings go.
>
> So the more I think about it, it sounds like your workflow is
> introducing too many
> conversions somewhere.   I think you are somehow printing the Ink Black
> simulation
> of the soft-proof but I'm not sure how that could be happening.   Are
> you printing
> directly from Photoshop using the Print with Preview screen?  Might you
> be
> printing the proof instead of the source file?   Are you printing with
> the QTR driver?
> The more you can elaborate your workflow the better.
>
> Roy
>