Epson ABW Color Wheel Question

[IanBarber]

I am trying a new paper Permajet FB Mono and I am experiencing a blueish cast in the shadows.
Having measured a black to white step wedge with a SpyderPrint I am getting these L values

The first column is L the second is a and the third id b
The second third and fourth values of b are quite high negative values so I am guessing this is where the blueish tint is coming from

12.51   -0.04 6.65
31.13   0.50   -5.12
37.88   1.21   -5.61
42.21   1.28   -4.06
44.99   1.13   -1.64
53.57   1.10   -0.83
63.57   0.44   -0.26
73.45   1.72   -0.90
82.30   1.46   -0.80
91.02   1.37   -0.60
99.66   1.05   0.36

In the ABW color wheel, am I correct in thinking that if I was to move the centre + more toward the Magenta this may reduce the blueish tint ?

Ian

[digitaldog]

It's a black box, you'll have to futz around to get there. I think if blue, you'd move in the opposite direction to yellow?

[IanBarber]

It's a black box, you'll have to futz around to get there. I think if blue, you'd move in the opposite direction to yellow?

Thanks Andrew.
I know it's not going to be an easy task but thinking about it, yellowfins is the opposite of blue so I think you are correct there.
Thanks again

Ian

[unesco]

What printer, OEM inks?

There is something unnatural in your data. For black is there 6.65 or -6.65?

ABW is quite neutral, and here looks to have sudden jump for darker tones to blues (assuming -6.65).

[IanBarber]

What printer, OEM inks?

There is something unnatural in your data. For black is there 6.65 or -6.65?

ABW is quite neutral, and here looks to have sudden jump for darker tones to blues (assuming -6.65).

The Darkest Black is

L
12.51

a
-0.04

b
6.65

[Doug Gray]

What printer, OEM inks?

There is something unnatural in your data. For black is there 6.65 or -6.65?

ABW is quite neutral, and here looks to have sudden jump for darker tones to blues (assuming -6.65).

Exactly. ABW is quite neutral. I've seen these sorts of shifts printing step charts in color mode but not with ABW. In fact this looks much closer to what my Epson 9800 prints unmanaged in color mode than in ABW.

The step changes vary widely. The B* shift of 12 between the two darkest patches will create a very noticeable hue shift on gradients at these levels. Especially annoying in B&W prints unless you desire the effect for artistic purposes. Also the L* gradient changes rate by 6.6 times between the largest and smallest steps.