Is there a new chart throb application. If than can ypu please give a link for it.
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From:
Alan Vlach ;
To: ;
Subject: Re: [QuadtoneRIP] UV transmisison characteristics of Epson K3 inks
Sent: Mon, Mar 10, 2014 3:07:11 PM
To: ;
Subject: Re: [QuadtoneRIP] UV transmisison characteristics of Epson K3 inks
Sent: Mon, Mar 10, 2014 3:07:11 PM
Roy,
Chartthrob has a new function to create a negative curve. It is applied to a positive image and inverts it while applying the curve. I plugged this curve into a QTR profile and didn't get what I was expecting.
Anyway, I created this curve using the chartthrob negative function:
I created this QTR profile using the above curve:
# QuadToneRIP curve descriptor file
#
# PRINTER=QUAD3800 Salted Paper
# TPF100 Ink limit =100
PRINTER=QUAD3800
CALIBRATION=no
GRAPH_CURVE=yes
N_OF_INKS=8
DEFAULT_INK_LIMIT=100
LIMIT_K=35
#BOOST_K=80
LIMIT_C=35
LIMIT_M=1
LIMIT_Y=35
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=35
LIMIT_LLK=1
# Describe usage of each ink
# All inks must be listed
# Gray Partitioning Information
N_OF_GRAY_PARTS=1
GRAY_INK_1=K
GRAY_VAL_1=100
GRAY_INK_2=
GRAY_VAL_2=
GRAY_INK_3=
GRAY_VAL_3=
GRAY_INK_4=
GRAY_VAL_4=
GRAY_INK_5=
GRAY_VAL_5=
GRAY_INK_6=
GRAY-VAL_6=
GRAY_INK_7=
GRAY_VAL_7=
GRAY_INK_8=
GRAY_VAL_8=
GRAY_HIGHLIGHT=0
GRAY_SHADOW=0
GRAY_GAMMA=1.5
GRAY_CURVE=/Users/windeking/Desktop/Curves/Chartthrobnegtest.acv
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
And printed this step wedge:
I expected to get this result:
But this is what printed:
As you can see the 0% or 255 value printed white instead of black. The gradient at the top of the wedge showed the darks printing till the very end where it printed white again.
I opened the step wedge in photoshop and applied a levels layer which changed the output value from 255 to 254:
I printed this image and got the expected result.
I'm also curious about the choppy look on the right hand side of the gradient.
Thanks for all your help,
Alan