questions about printing larger prints in LR

[owenpga]

Just viewed  the printing video of the Luminous Landscape Guide to Adobe Photoshop Lightroom 2. Very enlightening but a few questions remain unclear. Jeff Schewe mentions uprezing 50% to produce better prints. but doesn't really go into any detail about it.
lets say i have a image on screen that i want to make 20x30 and the native resolution goes down to 180ppi when i size it to these dimensions. i could print at 180ppi, but based on what Jeff is saying there is a better way. I need some clarity on the next step. do i click on the print resolution button and uprez to 270ppi (50%) or do i export the original and change the dimensions and resolution there and import back into LR? Any clarity on this subject would be great. thanks, Owen

[Schewe]

lets say i have a image on screen that i want to make 20x30 and the native resolution goes down to 180ppi when i size it to these dimensions. i could print at 180ppi, but based on what Jeff is saying there is a better way. I need some clarity on the next step. do i click on the print resolution button and uprez to 270ppi (50%)

Yes...that's what I'm saying. But you'll need to test this on your own images. The types of images that benefit are images with lots of high frequency textural detail or strong high contrast diagonals or circles.