Digital BW, The Print

Hello Keith,

I'm pretty sure the 2400 does not use Vivid Magenta.

> I just swapped out my light magenta and magenta carts in the last couple of days and now my prints show a distinct magenta cast.  Up until today, I have been able to achieve very neutral blacks with the K3 inks and ABW on my 2400, but know, it looks like I have a huge amount of work to do to figure out new settings to use to get back to neutral blacks.
>>>>>

This is very common, happens to me regularly.  My theory is that because the 2400 carts are not pressurized (like the larger models), the amount of ink in the mix changes as the carts empty and the internal pressure is reduced.  I also suspect that there may be differences among production batches of ink, because sometimes the differences are greater than other times.  Correct theory or not, it happens.

For me the shift is always along the horizontal green/magenta axis, and I compensate by moving the horizontal ABW setting along a 4 point range from -1 to 2.  Any time I change a LM or LC cart (and to a lesser degree the M and C carts) I usually have to run a few test prints to find out where the new horizontal point is to maintain my favorite tone.  I don't have to move the vertical setting.

Now and then, if I'm paying close attention, I'll need to make a slight adjustment as as one of these carts gets down to the last 20% or so.  Typically a new LM cart looks pinkish so the setting goes down to -1, and as the cart empties the setting moves to 0, then 1, then 2.  But not always - remember that the other carts are also changing.  If they all change at a similar rate the system may stay closely balanced for a long time with differences too slight to notice.  The rate at which the different carts are emptied depends, of course, on the images being printed.  So it's very complex and rarely the same with each cart change.

The changes can be so incremental over time that it's easy to miss and your eyes adjust along with it.  For this reason I keep some master reference prints around to occasionally compare the tone with current output.

Just to complicate things, I have on a few occasions seen a green/magenta difference after changing a LK or LLK cart.  But not often.  This is probably due to the nature of the particular image being worked on at the time.  And any time more than one cart is changed, the odds are greater for needing an adjustment.

It's possible that there have been minor shifts that you may not have noticed, but in this case where M and LM were both changed at the same time the difference is more pronounced.  I don't think there is anything wrong with your printer.  It's just the nature of the beast.


Regards,
Clayton


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