If you are a photographer printing to standard sizes is the most logical option to save cost (and eventually for framing purposes)
In order to make your images PRINT READY
Go to: IMAGE --> IMAGE SIZE
Make sure CONSTRAIN PROPORTIONS is selected
While in IMAGE SIZE, change the largest print dimension (H or W) so that BOTH dimensions are smaller than the dimensions of the standard print sizes.
The dimensions DO NOT have to be exactly a standard size but they should be smaller than the standard paper size.
Save as: FileName_paperHxW.jpg
In order to make your images PRINT READY
Go to: IMAGE --> IMAGE SIZE
Make sure CONSTRAIN PROPORTIONS is selected
While in IMAGE SIZE, change the largest print dimension (H or W) so that BOTH dimensions are smaller than the dimensions of the standard print sizes.
The dimensions DO NOT have to be exactly a standard size but they should be smaller than the standard paper size.
Save as: FileName_paperHxW.jpg