PDF export is clean printed file has white around transparent images

[astoryof355226334rsd]

Hello,

I have an issue where the indesign file and the pdf file are clean and look great.  When I send to the printer some of the images have white blotches around them.  I have shared 2 different places where this is happening.  Some of the images are from the printer so they are not great but you can see the white bloches.  I am not a graphic designer and have been using the program and learning as I go.  Any help would be appreciated as I am looking to get this printed. Thanks

[reproo2773183]

PDFX1a would hopefully fix the original problem.

Big downsampling is clumsy, presenting a RIP with images above its output resolution (usually 2400 or 2540dpi) sometimes gives very poor results. Out of InDesign I'd try Downsample to 600 with zip compression, going to 1200would only improve a little and only if output to a 2400dpi plate.

 

[notannhavoc]

please can you elaborate?  your image is helpful but I don't understand what the different colored labels mean - I'm mainly concerned with the color space flattening and want to try to avoid  laboriously converting all images to either CMYK or greyscale as appropriate manually. And how to "out of InDesign try Downsample to 600 with zip compression " where in acrobat?

[reproo2773183]

InDesign > Export to PDF > Compression > Images > Downsample to 600 above 601, Compression ZIP

ZIP compression is lossless and for these types of image should give you good reduction in file size.

The PDFX1a is still converting to CMYK for you and flattening.

InDesign>Edit>Transparency Flattener Presets

you could try making a new one with gradient and Mesh at 600.

But I don't know whether its in play for your file?

[rob day]

Out of InDesign I'd try Downsample to 600

If you look at the sample PDF @notannhavoc provided above—story of and - june 29acrobat saved as x-1a-1.pdf— the downsampling was set to 600PPI, and did include JPEG compression.

Even though the art has been saved as RGB PNGs it is effectively black & white line art—line art with very fine lines—which typically need considerably more than the standard image rule-of-thumb res of 300PPI. I would make sure the printer is not treating the line art as images and letting the RIP downsample them to 300PPI. Ideally the illustrations should have been created and left as vectors.

[reproo2773183]

I've just printed the PDFX-1a PDF on my digital toner Press (fiery RIP) there is no sign of the Color Space / flattening white squares. I tried both 600dpi and 1200dpi resolution settings on the Fiery, very difficult to tell the difference.

At full size, with the naked eye and looking under a linen tester I can't distinguish any jpeg noise against against the screening pattern in the background.

I output  a piece at 300% size and yes you can see the jpeg noise but only if you go looking for it.

The Jpeg noise is an easy fix – change the compression settings when you make the pdf, (assuming its not actually in the original image).

However, if I'm being fussy, the line drawings at full size, are very thin, they don't have the same prominance on the page when printed as they do on screen. Experience is telling me that if you print on a digital press with 1200dpi setting it will be sharper but thinner so probably less prominent to the eye than 600dpi. If its Litho then yes you'd get a super marginal gain, but for digital I'd guess worse.

As Rob wrote, ideally these would be vector. For Line-Art the next best choice would be Bitmap TIFF. But you are starting with color image.

[rob day]

I've just printed the PDFX-1a PDF on my digital toner Press (fiery RIP) there is no sign of the Color Space / flattening white squares.

Yes, I know. I don’t see any of the print problems @astoryof355226334rsd is showing either from my RIP driven large format Epson printer or my $200 Brother laser printer. Seems pretty clear that the problem is with the printer.

[reproo2773183]

I've been able to generate some of these artifacts from the original transparent pdf without pushing through a RIP. I've used Acrobat's "Flattener Preview" Tool. The artifacts don't appear in the preview window but do appear after flattening the page.

The Original PDF is sRGB images on a 33%k background, pitstop is telling me the images in the pdf are ZIP compressed and 300ppi.

All I can deduce is that when flattened the rotated objects are re-rendered and no-longer rotated.

IF the Compression settings for flattener-generated images are set to JPEG you get these artifacts.

IF you set to ZIP you don't get the artifacts.

I can't generate these artifacts on un-rotated images.

I've a few RIPs here and I've never seen one that gives flattener-generated image options. But this might be the smoking gun.