Print Booklet Image Compression and Downsampling
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- This topic has 6 replies, 3 voices, and was last updated 6 years, 1 month ago by
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I’m trying to figure out how to control settings for image compression and downsampling when using the print booklet feature in InDesign. In a typical export, these settings are under “compression”, and I set my exports to downsample images above 600 to 600. When I print a booklet it seems to be downsampling images over something like 450 to 300. Many printers can print higher than 300dpi.
Anyone know how to set the threshold when printing booklet?
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Brian
300dpi for continuous tone images is the industry standard for offset printing.
Screen ruling for high quality printing are usually 150-175lpi (or 25-20 micron second order stochastic screen).
A 150lpi screen can only reproduce image data to a certain size, files larger than 300-350dpi will lead to larger files and normally no visible increase in quality on the final printed page.Don’t get the dpi of a platesetter confused with dpi of an image. Platesetters usually run 2,400 to 2,500 dpi to product the screen rulings of 150-175lpi.
Keep the image sizes practical, Many times I have received artwork for a label with almost 1GB of files due to designers not scaling images or not cropping images but only having a fraction of an image showing this just making working on these files much slower than required (bring back a good finished artist to get the files right)
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Graham, even if that’s the case, I would still want to control the output. What if I have to scale down to 150 like you said? Also, I have had printers ask for 600 dpi images. I trust my vendors and if they ask for 600 I’m not going to give them half the quality. Even if they’re wrong about their own equipment, its no skin off my back.
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I did not say to down sample to 150dpi, I said the screen ruling was 150lpi. Rule of thumb image resolution should be about twice the screen ruling so 150lpi means images 300dpi.
Think about the images in an A4 booklet, if an RGB image is a full page it will be 25MB @ 300dpi or 100MB @ 600dpi that is a lot of extra data that will not be able to be seen.
If you are outputting a PDF for the printer then choose PRESS QUALITY and the images (colour and grayscale) downsampling will be set to downscale images 450dpi and above to 300dpi at maximum quality. Why is this the standard? Well the files are larger than needed and the quality is as high as can be produced on a high quality offset printing press.There are many people running digital press these days that lack knowledge of the printing process. You also get this with large format printing where an inkjet might be 1200dpi do you want to supply a 1200dpi image file for a 1.2mx5m print? (600dpi would give you a 9.GB file).
Continuous tone images are forgiving, where you will very high resolution is with BITMAP images. This is why you would try to use vector images for logo etc rather than making bitmap images. -
You definitely seem to know what you’re talking about and I do want to look into the dpi output of offset. I just went back and yeah, I misread your post. I read an instance of lpi as dpi. But that’s really not why I made this post. That will take some research and I’ve got every print vendor I’ve ever dealt with saying 300 is the LOWEST you want to go, not the MAXIMUM. If you have links to share on 300 being the max, Id love to read them.
I’m trying to find out how to precisely control compression when using the print booklet dialogue in InDesign The same way I can in the COMPRESSION section of the EXPORT dialogue. I am not using the Export dialogue. PRESS QUALITY is an option in EXPORT, not Print Booklet.
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Here is an Adobe’s take on the matter.
https://forums.adobe.com/thread/370714
See this section.
For offset printing, the standard image resolution is 266-300 ppi at 100% image size, for printing at 133-150 lpi; providing a ppi/lpi ratio of 2:1. This allows for a bit of “wiggle room” if you have to make a small or last-minute increase in image size without scanning again. If you remove the safety margin, you can use a ppi/lpi ratio of as little as 1.55/1 without image degradation (according to Agfa, a leading manufacturer of imagesetting equipment). You can certainly use images that are sampled at somewhat higher rates. But there is no benefit. It won’t give you more detail in your printed image due to the limiting resolution of the halftone screen.
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