p.1 #2 · Lightroom: print or export for online printing of specific aspect ratios
you dont need to make temporary virtual copies.
In the Develop module create your crop and export as jpeg. Remember, LR is non-destructive. The original image is unchanged and you can go back to the Develop module, change the crop, re-export, etc . If you prefer the idea of virtual copies existing at multiple different aspect ratios you can do that, but it is unnecessary.
Is there a downside in using the Print Module? I havent used it for crops, but I think you might have less ability to move the crop, rotate the image, etc.
p.1 #3 · Lightroom: print or export for online printing of specific aspect ratios
Scott, I feel that it takes too long to do the export of images one at a time, that is why I make the virtual copies and then export all of the same aspect ratios at the same time (usually tagging them with a color label so I can quickly filter them from the "regular 4x6" prints). Also, I would like to preserve the original size images in my catalog. However, I do appreciate your insight. Thank you.
p.1 #4 · Lightroom: print or export for online printing of specific aspect ratios
The only reason I could see for doing this in the Print Module would be to add final output sharpening and up the resolution to 300, 360, or 400 ppi for a specific printer.
p.1 #5 · Lightroom: print or export for online printing of specific aspect ratios
I just found out that when you use the Print Module to create the JPG, the only thing in the EXIF data is the copyright. So that bit of info might be useful for some.