Sharpening for huge banners

[Metalstrm]

I'm doing a commisioned promo banner, which is done except for sharpening. How do you guys sharpen in this case? And where? This is going to be printed very large (4.5m x 2.5m or ~180in x 100in).

Grazias!

[RDKirk]

First, be sure to communicate clearly with your printer to understand how much sharpening his raster image processor (RIP) will do for you. If at all possible, see if you can arrange to test a crop of the finished enlargement size.

I personally find that I still need to do considerable sharpening of very large images even before they go through my printer's RIP.