Digital BW, The Print

> 
> I have MIS quadtone inks in the epson 3000.
> 
> My stepwedge is blocky by ink cart..
> 
> Is the chart supposed to be smooth?
> 
> Here's my attemp at a curve;
> 
> PRINTER=Quad3000
> CURVE_NAME=3000q4test2
> GRAPH_CURVE=YES
> N_OF_INKS=4
> DEFAULT_INK_LIMIT=70
> BOOST_K=100
> LIMIT_K=
> LIMIT_C=30
> LIMIT_M=30
> LIMIT_Y=30
> N_OF_GRAY_PARTS=4
> GRAY_INK_1=K
> GRAY_VAL_1=100
> GRAY_INK_2=C
> GRAY_VAL_2=63
> GRAY_INK_3=M
> GRAY_VAL_3=43
> GRAY_INK_4=Y
> GRAY_VAL_4=13
> GRAY_HIGHLIGHT=0
> GRAY_SHADOW=0
> GRAY_OVERLAP=0
> GRAY_GAMMA=1
> GRAY_CURVE=
> N_OF_TONER_PARTS=0
> TONER_HIGHLIGHT=0
> TONER_SHADOW=0
> TONER_GAMMA=1
> TONER_CURVE=
> N_OF_TONER_2_PARTS=0
> TONER_2_HIGHLIGHT=0
> TONER_2_SHADOW=0
> TONER_2_GAMMA=1
> TONER_2_CURVE=
> N_OF_UNUSED=0
> 

From what I can see :
- Boost is set too high, overspraying K. You want boost to be 110-
115% of Default Ink Limit thus around 77-80% in your case.
- All Gray Val seems high but I don't know the ink set, so it might 
be valid. However you do not need to limit CMY which are you grey 
densities, since the Gray Val already establishes the relationship 
between K and greys.
- Shadows and HLs 'd better be smoother (like you'be doing with a PS 
master RGB curve to open up shadows and calm down HL), you need to 
input some datas, probably around respectively 10 and 8. You can load 
a PS curve if more convenient to adjust these.
- You also want greys to overlap for better smoothness, specially for 
K, this could be 10. 

Those are standard values and a fairly common start to generate the 
linearisation.

You can now create the curve and visualise the usage of each ink. Let 
me insist on this : you can analyse a lot through those graphs 
without the need to print. I past tended to under-estimate this nice 
feature, it's a free $, time, hassle testing.

Now, print your stepwedge and measure each patch, those values have 
to go into the linearisation panel of QTR, you click to get the 
linearisation done and you will see the total ink usage curve, the 
smoother the better in my experience.

Print the stepwedge for final evaluation and you're set. Next is to 
use the profiling tool of QTR with this lastest stepwedge. Other 
approaches use gray spaces or Paul's adjutment curves depending on 
equipment and the way one feels more comfortable.

Hope it helps.

Olivier