Printing a color document with a png image

[smallrain]

Hi, I am having trouble placing a logo in InDesign. The logo image is a vector on transparent background, so to preserve transparency and not create pixelation (jagged edges) I have saved it as a png file. It looks ok on screen. But PNG converts to RGB which isn't good for commercial printing. The Indesign document is saved as a pdf before going off to the commercial printers who need everything in CMYK... Any advice gratefully received!

[Dave Creamer of IDEAS]

PNG is a raster (pixel) format and could look "okay" when printed. InDesign can convert RGB to CMYK, but you might experience color loss.

If the logo was truly vector, you should be able to place it directly. A native Illustrator (.ai) file will support transparency; an EPS file will not show a background unless something is in the actual art (like a white box). 

Can you give more details?

[smallrain]

Hi thanks for your reply. I have just tried placing the image as an ai. file - it appears in the Indesign document as a PDF  and while it keeps the background transparent ok, the vector line is jagged (pixellated) - I've taken the vector from shutterstock (off a sheet of vectors) and simply chnaged the color, and want to place it as part of an Indesign document for a book cover. The same happens when I try saving as .eps

[rob day]

If the .ai file is placed it shouldn’t print jagged—vector object have no resolution. The jaggedness could be your display performance setting. The display setting and zoom magnification will affect the preview, but not the output:

Typical Zoomed out:

High Quality display zoomed out:

Zoomed in you can see the vector is better than the PNG:

If a composite printer is printing it jagged there's something wrong happening in the driver or the link is missing. For offset printing you would never want to use a bitmap image in place of a vector object

[smallrain]

Many thanks for this and to Bill too. Really helpful! I hadn't thought about it being a display issue. I've just exported the Indesign doc to PDF, with the .ai file placed, and the image is no longer jagged and looks ok zoomed in and out. So hopefully it will print ok too! Not sure why it looks jagged in Indesign but i will have a look to see if I need to change any display settings. Thanks again

[smallrain]

I should maybe add that I'm running it on Windows 10 on a PC, in case anyone has any insight into that. Now I've found a way to do it, it's off to bed (uk time!)

[Bill Silbert]

Converting an .ai file to a png file actually creates the possibility of pixelization. Also, since png is a raster format it is totally resolution dependent and will start to fall apart with any enlargement. For printing (and possible future editing in Illustrator) save the file as an .ai with pdf compatibility. You can also retain the vector qualities by saving out of Illustrator as a pdf (use PDF X-4 if you need to retain transparency).

[smallrain]

Hi Bill, thanks for your reply. See my comment on the previous post - placing the image as an .ai gives the vector a jagged edge...

[Bill Silbert]

Do you have your screen view set to High Quality (under the View Menu)? An imported file will look pixelated when the screen is showing Typical View.

[smallrain]

Hi Bill, yes it's set to high quality

[rob day]

Whether you really get high quality can depend on available memory. I’ve seen cases where High Quality degrades when memory is short. Make sure you judge zoomed in 400%+. Also, make sure the Link Status is listed as OK