Message
Re: [QuadtoneRIP] Re: Ink limit low limit
2015-01-28 by sanking@...
I could achieve the same UV density range by using a 33 1/3 % dilution of PK and increasing ink level to 36, but the resulting negative would not be any smoother, and the much greater amount of ink would be wasteful and probably cause smearing and pizza wheel marks. Regardless of whether you use a 100% dilution of PK or a 33 1/3 % dilution of PK, if the result desired is a negative with a given density range you will have to put down the same amount of pigment particles, regardless of dot size. So from my perspective you gain nothing by using more ink of a weaker dilution, and risk a lot.
With this profile I use the LINEARIZE command for a given process, then use the K curve to adjust for slight process variations. I am attaching the profile with LINEARIZE off (# in front of command) and K curve set to give linear output.
Again, this profile is for making digital negatives for carbon transfer printing, not for making digital inkjet prints on paper. Also, some of the commands in the profile are not operative with the single gray value system, gray gamma, gray shadow and gray highlights, I just keep the numbers in there because they are default values that are used in creating the .quad file.
Sandy
#CURVE_NAME= Carbon-8K-12
#Based on Carbon Tissue #232, 15 grams of Black Cat Ink + 3 grams of Mixol #23 Dunkelbraum + 1 gram of Mixol Oxide Red #4, with tissue coated to a wet height of 1.0 mm.
#Profile when printing a step wedge gives a DR (density range) of approximately log 2.15.
#With Tissue #232 sensitize with a 3.5% potassium dichromate solution, diluted 1+1 with acetone, approximately 10 ml per 8X10 sheet, applied in two coatings with a roller. 300 ULF units. Dry tissue 60 minutes at RH 40%, with fan at three feet.
#This profile is based on a custom all-gray profile, the disposition of which is as follows. K=PK, C=PK, M=PK, Y=PK, LC=PK, LM=PK, LK=LK, LLK=LLK. The PK, LK and LLK are the blacks in the Epson K3 ink set.
GRAPH_CURVE=YES
N_OF_INKS=8
DEFAULT_INK_LIMIT=100
LIMIT_K=12
LIMIT_C=12
LIMIT_M=12
LIMIT_Y=12
LIMIT_LC=12
LIMIT_LM=12
LIMIT_LK=12
LIMIT_LLK=12
GRAY_HIGHLIGHT=4
GRAY_SHADOW=4
GRAY_GAMMA= 1
CURVE_K= "0;0 100;100"
COPY_CURVE_C=K
COPY_CURVE_M=K
COPY_CURVE_Y=K
COPY_CURVE_LC=K
COPY_CURVE_LM=K
COPY_CURVE_LK=K
COPY_CURVE_LLK=K
#LINEARIZE="18.23 19.41 20.55 22.06 23.84 25.54 27.66 30.37 32.73 35.33 38.25 42 46.59 51 56.07 62.24 70.26 77.91 86.35 91.78 94.36"