Again discussion has left me behind.

All said in done you should have more then enough data to get a tack sharp render at sizes over 36” at 72 DPI.

*Sounds like you're trying to balance dpi (on the printer) vs. pixels (on the screen). There's any number of ways to handle this depending what color scheme they use (Japanese, European, US, etc), type of printing (halftone [get real..:]), CYMK, etc. Any good printing service is going to be able to compensate for whatever you're looking for. *

Again in dumbed down terms.  Pls explain what kind of render sizes are adequate to produce acceptable printed image of 16X20inch or as large as Bambam's 33". 

  I guess it is the dpi vs pixel thing that fuzzies my brain.  Is a simple table or rule of thumb not available to set pixel size rendered to produce an apparent non-pixelated print  of varing size?

I follow the increase ray/pixel setting giving a more accurate color per final pixel.  Then I get lost again at :

B*:  All other setting are at defaults value except for Optimization which is set to aggressive and Post processing set to 48 bit dithering.   *

Again thank you for indulging my ignorance on this subject.

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