This does Not explain Rhia474's quality issue.
But this explains the Resolution Quality when 'Rendering for Print' (as opposed to Web)

There are Three different properties that will effect the PRINT Quality:

Pixel Dimension - the Area of the Image (Width & Height)
Document Size - the Size of the paper (print media)
**the Resolution - Dpi, Dots/pixels per inch (how many Dots/pixels to put on paper in each inch...limited by the Print Device)

As JoEtzold pointed out, if you do NOT let the image editor Resample the "Pixel Dimension" then you can change the Resolution by manually changing the "Document Size" or the "Resolution". This has No Effect on the Rendered "Pixel Dimension"

Therefore the Pixel Dimension becomes anchored.

These are snap shots of the Render I have that started this all:
**Inputted to Poser12 was 3300x2550 Pixel Dimension, 300 Dpi, which also in Poser showed Document size of 11x8.5

#1: As it opened in PhotoShop (Document Size changed but Pixel Dimension is proper)

#2: What happens if you change Resolution (Dpi,pixels per inch) it Changes the Pixel Dimension - THIS NO GOOD, BAD QUALITY PRINT

#3: Just Notice on This one how Unchecking "Resample" now Disables the Pixel Dimensions section.

#4: Now I can change either the Document Size or the Resolution values and manipulate to the Printer 'How many Dots/Pixels to print per inch' - This is GOOD. (I think)
I now have the Same Dimension of Pixels that Poser rendered, I just tell the Print Device how to view it.

Again, comparing #1 and #2:

I want 300dpi in a 3300x2550 Dimension of Pixels, NOT 13749x10624 Dimension.
And I want it on a sheet of paper 11x8.5 not 45.8x35.4

So basically I think Poser is kinda getting it right, only issue is that the saved File has to have it's Document Print Properties corrected (BEFORE sending to Print) for the target you were telling Poser....