K7 GO incompatible with Ultra HD Matte Black?

InkjetMall Customer Support Piezography Inks & Printing
1

I’ve been experimenting with using the original K7 second pass GO on matte prints made with an ultra HD MK K7 set and when the GO is applied, it greatly decreases dmax. I’d read in other threads that the GO on matte prints will slightly increase dmax. Is this only true with the original non ultra HD MK ink?

2

This depends upon the paper and the amount of GO applied. In general it did not change the dMax at all with a lowish (25000-30000) amount of GO on a standard paper like Photo Rag and the original Neutral 1. But the UltraHD is so damn dark I could see this effecting the dMax negatively a bit. Not sure where you saw the post on the dMax increasing after GO on matte. It changes the color a bit but does not increase dMax on matte papers exactly. Maybe on some . . . most not.

best,
Walker

3

I can’t remember when the post was, but I’m mainly interested in using it for the increased archival qualities. I used a QTR flush image and calibration mode at 25% rather than a GO curve, and with that amount saw a reduction of about 1.5 L.

4

Print the GCO at the same time (LLK channel) and then simply zero out the GCO in the darkest points of the curve (last few rows). The UltraHD is 100% pure carbon so the shadows on these prints will basically never fade (like ever) and are already high ink load thus fully filling the paper surface.

Actually, I think if you just take the LLK channel from the gloss curve and put those numbers into the LLK channel of a Matte curve it will already do this.

best,
Walker

5

Gotcha, that makes sense, only thing is I’m not using the GCO at all. I have an HD K7 neutral set, with 3 color toning inks in one printer, and then using a second printer for the GO. Works beautifully on coated paper and the HDPK, just haven’t had luck with the UHDMK.

Would the GCO as a second pass rather than same time printing have the same protective qualities as the GO? If not, are there any other protective coatings that can be loaded into an inkjet printer?