My resized down and sharpened (thru Unsharp Mask in photoshop) pictures are now 1800x1200 and they look sharp enough on the screen. They are mostly pictures of people (portraits etc.) in wedding ceremony and in a restaurant.
I've only done online photo sharing and through other digital means but never printed out at mini photo lab (like Fujifilm outlets) before. I intend to select about 30 to send to a Fujifilm outlet to print them.
However, I'm wondering whether it's necessary to sharpen them further for 4R prints at those Fujifilm outlets because they don't look as sharp as I would like them to be when I view them at print size (6"x4" @300 pi) in photoshop although they look perfectly fine on Windows screen viewing.
Thanks in advance.