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p0intblank
Oct 25, 2005, 11:12 PM
I am in the process of redesigning a postcard for a client and they need it so it can be printed at 300 dpi. I am doing this project in Photoshop and the only related option I see is ppi and I know that is for screen resolution. I know my graphic design terms, but I have to brush on my printing knowledge. Can someone fill me in real quick on how to get this document to be printed in 300 dpi? I will not be printing it; I am just redesigning it for them.

Oh and they also requested the bleeding to be 1/16". I know this is possible in Illustator, but how would I do this in Photoshop? Thanks a bunch!



ATD
Oct 26, 2005, 09:16 AM
I am in the process of redesigning a postcard for a client and they need it so it can be printed at 300 dpi. I am doing this project in Photoshop and the only related option I see is ppi and I know that is for screen resolution. I know my graphic design terms, but I have to brush on my printing knowledge. Can someone fill me in real quick on how to get this document to be printed in 300 dpi? I will not be printing it; I am just redesigning it for them.

Oh and they also requested the bleeding to be 1/16". I know this is possible in Illustator, but how would I do this in Photoshop? Thanks a bunch!


Most of the time they are asking for a PS file at 300 ppi (pixels per inch) to be printed at 150 dpi (dots per inch). The general rule is that ppi is double the dpi. Most color presses run between 133 to 150 dpi. 300 dpi seems high, I would check with the printer again. To create more bleed add 1/8" to your Canvas size in PS (Image/Canvas size). Don't do this in Image size, that's different. You may have to clone your image outward to fill to the new edge. When you bring this into a layout program, you will need to see the whole image with bleed, then you will be creating crop marks that will show the finished size inside the bleed. Hope that gives you a start.

zelmo
Oct 26, 2005, 09:25 AM
We output most everything at 175 line, occasionally running as high as 250 (the upper reliable limit of our Agfa plates). Most printers I know output film/plates at 150 or 175 line screen, and want images to be 300-350 dpi at the actual printing size. In other words, an 4 x 5 image at 300dpi that is being enlarged 200% to 8 x 10 will have half the resolution and look like crap (to use a technical term ;) ).

p0intblank
Oct 26, 2005, 12:11 PM
Thanks for the help, guys. Unfortunately they are already going with someone else. Oh well, it happens to all of us. :rolleyes:

At least I got the information down. :)

Sparky's
Oct 29, 2005, 04:31 PM
Though a bit dated the info at this site is still relevant:
http://graphicdesign.about.com/library/weekly/aa070998.htm

And probably the clearest explanation I have found on-line.

But this one is shorter:
Tip #85 - DPI vs LPI vs PPI...
I still don't understand this whole lpi/dpi thing... we're preparing ads for newsprint... HELP the graphics look awful!

DPI = Dots per inch = units used to measure the resolution of a printer
LPI = Lines per inch = The offset printing 'lines' or dots per inch in a halftone or line screen.
PPI = Pixels per inch = the number of pixels per inch in screen/scanner file terms.

Don't be confused by the terms. David Blatner introduced us to SPI in his 1993 "Real World Scanning" book (highly recommended) meaning "samples per inch".
__ In terms of output which is going to the newspaper, let me throw a wrench into the whole project here... since newspaper reproduction is so poor, and you're left at the variables of the press and paper, it sometimes matters not how good the original image is, or your hard image editing work. It still turns out lousy. If you've ever stood at the end of the web-press and watched the ink fountain ride up, then down, you'll know what I'm talking about.
__ Here's a new twist: how about NOT sending the paper a halftone, or any photo that needs screening and send straight line instead? (Some of you stepping back in shock.)
__ Take your image, convert it to grayscale, then making sure the resolution is at least 300 ppi, convert it to a "Dithered" bit map? Try this and see if the results are not very much like the famous Heliographs which always reproduce wonderfully in newsprint.
__ Now, if you must go halftone, here's the key
__ LPI x 2 = PPI.

In other words the minimum for faithful reproduction is 2-times the line screen in use. Many of the purists will say 2.2 times. Okay, go with 2.2.
__ So, if the newspaper is using an 80 line screen (many do) then you should have a minimum of 160 ppi resolution. Better yet... find or create a graphic in Illustrator and supply it to the paper as a true line shot. That way you're sure it will be a hit!