Pankaj Purohit , Jun 06, 2009; 04:06 p.m.
Screen resolution is usually 72 DPI and print resolution is usually 300 DPI.
If you want to show the coin in its real size than you should know its dimensions and than open a new document/image in photoshop and set the desired paper size for the print, don't forget to set the dpi to 300 (while assuming that you are foing to print it at 300 dpi. Now set on the rulers and place the guidelines for the desired dimensions of the object, now open the desired object's image in photoshop and copy it and than paste it into your new document/image where you performed the upper described steps. now resize to match the object's size as the guidelines.
Here is the new window parameters :
New image window : asuming that you want a print size of 8X10