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I'm trying to save clip art in .png format so I can preserve the transparent background (I realize .png is usually used for web graphics.)

My problem is that my images are absolutely huge. When I save a 4 inch graphic (canvas trimmed) as a png-24 and then attempt to place the file it is suddenly 18" tall. The quality of the image in fantastic, I just want to save it to a smaller size.

I've looked all over the web and tried different settings in Photoshop, but can't seem to solve this problem. What am I doing wrong?

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  • What DTP (Desk Top Publishing) software are you using to produce the artwork for print? If you are using something like InDesign you are able to now import the .psd instead of creating a cutting path in a .tiff and therefore you can set the background to transparent before you import.
    – sisham
    Dec 3, 2012 at 16:36
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    That's weird, the document size shouldn't change at all. How do you know it's 18 inch? Does it become an 18 inch print, or..?
    – paddotk
    Dec 5, 2012 at 22:44
  • You say "place the file": in what application, and are you printing from there? This is critical to be able to answer this question.
    – e100
    Dec 11, 2012 at 13:04

4 Answers 4

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  • If you are indeed working on a print project PNG is an incorrect format to use. Many Raster image Processors (RIPS) are not designed to handle PNG images. Appropriate formats are EPS, TIF, PSD, and sometimes JPG. But these should be in CMYK format, PNG does not support CMYK color.

  • Image resolution (ppi) needs to be a minimum of 240 to produce a good quality image on press. PNG images, since they are for the web, do not support PPI readings. (This is why you're seeing a large image as well) This, again, is why the other formats are used.

  • If you need transparency, you should use either a mask or clipping path to indicate transparency in one of the correct image formats - EPS, TIFF, PSD.

  • Explaining what software you are using beyond Photoshop would be helpful in providing answers.

In all cases of professional print production, PNG is an incorrect format to use for any image.

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It is important to understand that images are stored and measured in pixels, not pixels per inch. Print production is traditionally predicated on about 300dpi, so if you want a 4 inch square image (when printed, since inches don't exist in computers), you need to provide 1200x1200 pixels to meet the specification.

Further, it is my understanding that the notation of desired or intended ppi/dpi is not even supported by the PNG-24 file format.

In other file formats (such as TIFF), DPI is merely a flag (or suggestion) to software, but the only thing that matters is how many pixels there are.

In the absence of a dpi flag stored in file, the software working with the file must guess, and the typical default is probably going to be screen-based which is traditionally 72 or 96 ppi. Considering that 18" (actual) divided by 4" (desired) is 4.5 and 72 x 4.5 is about 320 then my guess is that in Photoshop your image settings are 320dpi; 4 inches wide; 1280 pixels wide. (1280x720pixels is close to the 720p standard screen resolution).

In your specific case, the image when placed is too big: this is OK. All you need to do is set the percentage scale to the size you want and run with it (try 20-25% size). If you want to avoid this in the future, use a file format such as TIFF for print production. JPEG also stores the dpi flag AFAIK, but JPEG is a lossy form of compression which can degrade the print quality.

Note: to adjust the dpi in photoshop without altering the pixel dimensions, you can copy either the px height or px width value, alter the dpi, then manually change the px value back to what it was. This alters nothing but the dpi flag (you'll see the projected file size increase when you change the dpi, but then go back to exactly what it was when you revert the pixel dimension value)

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Check that the ppi of the source and final file are the same. Because screen is 72 pixels per inch, when you put that into a print document (usually 300ppi), it will be a lot smaller. (the pixels are over 4x more condensed)

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  • I think what John meant to say is that your art will be much larger. The number you want to look at in Photoshop is the Document Size. Regardless of the resolution, an app like InDesign will obey your document size specs. If you uncheck resample image before changing your DPI, you'll notice the document size adjust accordingly.
    – plainclothes
    Dec 3, 2012 at 17:23
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Save it, then compress it as a rar, then the delete original

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  • Please can the downvoters explain why? Never delete a origianl until you know exactly you will not need it longer! Compressing as .rar file was not asked as I understand the question. BTW: welcome to GraphicDesign.SX!
    – Mensch
    Sep 2, 2013 at 16:49
  • The answer misunderstands the question: the OP's objection to size refers to the print dimensions not the file size. Additionally, RAR files are not typically supported by DTP compositing software ("attempt to place the file" implies for-print production software).
    – horatio
    Sep 3, 2013 at 16:17

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