Advice on smoothing an image please

[Ziaphra]

Because even though it looks correct on your screen it can detrimentally effect the print quality. ;)

[vhansen]

Perhaps because sharpness, or lack of,  is not usually caused by damage.  Sharpening could "enhance" and image, if done correctly, or add to the damage if overdone.

[Quoin]

As a matter of interest, why No Sharpening At All.

I Just read the info from link above - It says that it may look good on your screen, but it affects the print quality.