I made about 100 images (total since I installed the inks for the first time) and had everything calibrated for matte black with German etching using the Piezo pro K-4 inks. I then switched over to photo black to make a digital negative with the PiezoDN-ProK4. I then switched back to the matte prints. The printer did a normal cleaning and I did a power cleaning and when I made a print of the same image with the same profile, it came out warmer and darker. I only thing I can think of is to re-calibrate since maybe I still had some old ink from when I first installed the inks.
The other question I am wondering is, the printer is a 9900 with one dead nozzle, since I have it as the Pro K4, does it make sense to move the photo black to an extra nozzle and remap it since I have one free? This way I am not wasting so much ink when I switch between the two?
dual K printer? Yes, that makes sense. It will save money and cause less auto-head cleanings (or none) as there is no way to turn the K switch auto-check off. What happened most likely is that your printer did 3x enforced auto-head-cleanings unless you have this set to only do one per K switch. If you had not agitated you carts once or twice before sitting/printing that you pulled some old pigment into the lines and you are seeing this now.
Agitate every Monday or before any print session whichever is more frequent.
Since I don’t print on glossy paper I remapped the GO slot on my 7880 to MK as well as the few papers I use. No more wasted ink! I also agitate each cart on Walker’s schedule. If you aren’t doing this already there is a right and wrong way to do this. As I recall IJM has a video on the correct procedure. Basically you don’t want to introduce air into the nozzle area. Remove the cart carefully, point the nozzle down to a vertical position and shake back and forth, not up and down. Because of tolerances some carts can wiggle once they are firmly seated into the slot. For these I cut a strip of cardboard the width of the and about 2” long and used them as a wedge underneath the cart. No more wiggle!