Resolution question

Question

I am trying to create a sign that will be 24 inches by 72 inches when printed by a sign company.  I can't figure out how to send them what they need in terms of pixel inches with a requested resolution of at least 150 dpi.  I am starting with a scanned business card which is understandably a giant leap in terms of size.   Help!!!  and thanks. 

Answer 1

The text for your sign will be easy - if you use a Postscript font.  Postscript fonts - like Times, Times Roman, and Helvetica - are mathematically defined.  That means each letter isn't a collection of dots - which would lose their resolution when scaled up to perhaps a foot tall.  Instead, the letter "O" (to pick one at random) is defined by the mathematical formula for a circle.  Each letter has a different formula.  The net result is that they don't lose resolution when you scale them up.  I've printed individual letters ten inches tall using the Times font.  They looked sharp and crisp.
These scalable fonts are how desktop publishing got started.  At the beginning, you pretty much had to use the basic four postscript fonts - Times, Helvetica, Courier, and another whose name I've forgotten.  Now there are many more postscript fonts.  I know this because I owned a financial newsletter for 18 years.  We switched to desktop publishing in 1986 - four months after desktop publishing was announced.  I got started on Pagemaker (the first of the desktop publishing applications), and then switched to Adobe's InDesign.
As a computer fanatic, I was curious as to how the letters kept their resolution - even if you did something bizarre, like specifying that they should be printed at a font size of, say, 23.14.  The answer is this use of mathematical formulas for each letter.  When you scale up the formula for a circle (to go back to my letter "O"), you don't lose resolution.  That's how postscript works.
Basically, you aren't going to have a problem if you use a postscript font in your sign.  You are going to have problems if you want to include a picture on this sign.  There, the scaling is going to cause problems.
All that I've said is true if you work with a desktop publishing application or a word processing application.  I'm not sure what happens to Postscript fonts when you embed them into a picture.  I don't know if they remain Postscript fonts.  So be careful about using Elements to turn out the final product as a picture.
If you are thinking of having a sign printed, then you're probably already dealing with a commercial printer.  Talk to them and explain what you want to do.  They are the experts, and can tell you exactly what you need to do, the format you should use - and exactly how you should deliver the final product to them.
There are web sites that will license you very, very high-resolution pictures.  These would be, say, 20 megabytes.  Pictures like that could be scaled up without you having too many problems.