How can i make an image glow?

I want to make large format prints of cities and use led lights for antennas etc...?

• The question(s) are... I know a large format printer will print out a nice long poster style print for me. I want to make them long, so I will buy one that is wide format and long. What is the minimum DPI i should use? Also, if i wanted to add glow in the dark to parts of the image (like the moon) how could I make that work properly?

• Answer:

  As far as adding "glow", that would be done with a photo editing program like Photoshop or GIMP. It would take more space than allowed on here to begin a masking/layering/enhancing tutorial. For the printing/mounting...The best/easiest way to do this is to crop/size the image to the final print size with a minimum of 240DPI (300 DPI would be best....but without knowing the size/quality of the original, it is hard to make specific recommendations). Then save a copy (ALWAYS WORK WITH COPIES AND NEVER THE ORIGINAL), as either a JPG or TIF (I prefer TIF for printing). Take it to your local photo lab in an actual camera shop (NOT walmart/walgreens/etcetera) and have them print it AND mount it on Gatorboard. (It costs me $40 to have a 20"x30" photo printed and mounted with a 3 day turnaround). Once you have the mounted photo, put some scotch tape (preferably photograph mounting tape) over the spot you want the LEDs (fold part of the tape end under itself for easy removal) and use a Dremel tool to drill the holes for the LEDs. Once the holes are drilled, remove the tape, and add the LED and circuitry to the pack of the poster. ADDT'L: Sorry, I missed the "glow in the dark" part. You would need strontium aluminate phosphorescent pigments (also called glow in the dark).