Cropped Prints

[SAAER45]

I just got Photoshop CS2 and recently have been playing around with cropping. To develop my photos I always use shutterfly internet developing (you upload the files, they send you the prints). After doing some serious cropping on my shots from a recent trip to Alaska. I noticed that photos that were seriously cropped did not fill out the 4x6 prints. In other words, the photo was on the print, but the sides (or tops and bottoms) were just blank photo paper with no image. How can I fix this for my next developing, do I need to resize the photos to 4x6 in photoshop before I print them, and if so then how would I go about that?
Thanks,
John

 

[Big Mike]

If you are sending images to be printed at 4x6, then the aspect ratio should be 4:6. 1200x1800 pixels for example.

The crop tool does have preset aspect ratios (4x6 @ 300 PPI) (5x7 @ 300 PPI) etc.

When using the crop tool, you can also enter in the dimensions you want, at the top of the screen.