Larger print size results in darker prints - Need Help

[Ken W]

Large prints from Lightroom, using the same paper, printer profile, rendering intent, do not match the same size output from Photoshop or smaller size from LR or PS. Larger Lightroom prints have noticeably more density. The problem can be summarized from the result of two sizes of test prints I made using both LR and PS:

Comparing 9 x 18 prints from PS and LR: Prints look identical
Comparing 16 x 32 prints from PS and LR: LR print is darker. The PS 16 x 32 print is identical to the 9 x 18 PS and LR prints.

Some thing is causing LR to make the prints darker above a certain size ( I am not sure what that size is ). This is frustrating and I would appreciate any suggestions or feedback.

All prints are made on an Epson 7900 on Museo Portfolio Rag, same ICC profiles, same exact setup in the Epson printer driver (off no color adjustment), PS: PS manage color and same icc profile specified in both  Lightroom and Photoshop. The computer is a Windows 7 machine.

Thanks for your help

[madmanchan]

Do you have the "Print Resolution" box checked in the LR "Print Job" panel?

[Ken W]

Yes, it is set to 240 ppi, which is the standard resolution I have been using when printing from Lightroom.

[Ken W]

Solved. Somehow the custom media setting for the Museo Portfolio Rag paper was lost when I set up the LR template. The custom media setting reduced the color density by -20 in the Epson Printer driver. With out this setting the color density was at the default zero and the density was greater.

This brings up another question that I will have to explore. I arrived at the -20 color density setting when testing various Epson Driver media settings for the 7900 prior to profiling this paper after Epson replaced the nozzle heads on my 7900 printer. I found at the default zero color density I encountered banding. Prior to the replacement of the nozzle heads the default zero color density worked fine and there was no banding. Interestingly, on the 16 x 32 print that mistakenly used the zero color density setting there was no banding. Now I want to go back and redo my media tests. Is it possible that the new print heads needed a breaking in period and that is why I encountered banding on both the Museo Portfolio Rag and the Epson mat paper?