Hi guys i have a quick question.. im sure it has been addressed before and sorry if it has... i am trying to make a photo collage using photoshop.. and after im done with it iam taking it somewhere to have it printed 16x20 .. my question is... what size image should i do it in photoshop? what resolution? if theres anything else i need to do so the quality comes out perfect when its printed that big..  thanks in advanced..

Normally for printing you want at least 300 DPI.

So a 16x20 print would be a 4800x6000 pixel image.

 - Noel

thanks for the help

Call the print house thats going to do the printing and ask them what size and format they need.
Different printers have different requirements. For very large formats its often 150 dpi at full size

Yep - call the printer and ask THEM - believe it or not, sometimes you can even go down to 100dpi!

Often, some printing equipment (like a Lightjet or a Lambda) will do a slight version of "filling in the blanks" and smooth out stepping/jaggies. This saves not only YOU for having to create a huge file, but it saves THEIR SERVER and equipment from having to HANDLE it.

You'd be amazed at how low you can go and it still look great - especially the larger you go (billboards are often only 9, 12, or 36dpi!).

Hope this helps-
-Lew ;-)