Screen Artifacts on Transparent PSDs in Exported PDFs Can Be Deceiving…Most of the Time.
I’ve been using transparent PSD files from Photoshop since the release of InDesign 2.0. I still remember the first time I used one and experienced a feeling of wonderment I’d never felt before when laying out a page. I felt free from the rigors of faking backgrounds with full page TIF files or drawing clipping paths.
Like many of the other features of InDesign that have made our lives just a bit easier I came to take it for granted until the release of CS3. From early on I noticed horrible black halos around the edges of transparent PSD files on exported PDFs. It was very noticeable and was enough to concern me about how it would print. The good news is that for the most part it doesn’t except on lower end printers (hence the title of the post). I don’t recall seeing it print on a high res device but what to do about the on screen problem and the fact that your client may have a cheap ink jet and calls every time you send a PDF concerned about it?
First, let’s take a look the issue.
Below is a screenshot from InDesign CS3 with two identical files placed. On the left is a PSD file and on the right the same graphic saved as TIF. You would need to look very carefully but there’s some very fine artifacts around the edge of the PSD even when using high quality display settings. It’s not visible in the TIF file and the reason for showing you both will become very apparent as we move along.
A very faint black outline can be seen on the left. The TIF file displays smoother
If that was all there was to it, there wouldn’t be an issue. But take a look at what happens when that file is exported to PDF using InDesign’s predefined Press Quality setting:
A black outline is clearly visible in the PSD file. The TIF is fine.
Not a very pretty picture and certainly not something I would want a client seeing. I long ago swore off telling people “don’t worry, it won’t print like that” especially if the client’s “proofing” on a cheap ink jet that does show signs of the problem. The other issue is that not every PDF is destined for print. InDesign is being used more and more for interactive PDFs which are used for screen viewing only.
So, why is this happening? It seems that Acrobat is getting very carried away with trying to smooth the edges of those PSD files. A quick visit to Acrobat’s page display preference panel and you’ll see that in the rendering section, smoothing of images and line art are turned on by default.
Acrobat 9's view preferences. Depending upon the version, your's may differ slightly.
Let’s see what happens when we disable smooth images.
Much better!
It’s certainly a vast improvement but as I said earlier, that view is enabled by default and there’s nothing short of walking your clients through disabling it, that you can do about other computers.
What should you do? Possible workarounds are exporting PDFs where the transparency is flattened such as PDF X/1-a or printing to Adobe PDF which will always yield flattened artwork.
However, both of those choices can introduce stitching artifacts so you’ve just jumped from the frying pan into the fire. My solution is to just using TIF files for now (which is why I showed both versions in this excercise). For most purposes that’s fine. If you use layer comps or layer visibility overrides those features won’t be available with TIF so flattening my be a better alternative. Of course there’s always the old standby: “Don’t worry…it won’t print like that” combined with crossed fingers.
Another case where Acrobat lies to us is the thin white line syndrome, especially in flattened pdfs. I hear from people all the time about this: “Why is there a white line in my PDF?”?
It was Michael Stoddard who years ago taught me the best trick involving white lines: Zoom in on them in Acrobat. If you zoom in and the line disappears or stays the same tiny thickness, then it’s just a screen artifact and should not print. (I would say “will not print,” but as Bob pointed out, it might on some lower-end devices. But even there, it usually goes away.)
If you zoom in on a thin white line and it actually gets thicker, then you know it’s really there!
Again, if you turn off Smoothing in preferences, artifacts almost always go away.
Acrobat’s Smooth Line Art / Smooth Images preferences are really helpful for making things look nice on screen, but they sure can cause blood pressure to rise.
I’ve had very no problems with ‘artifacts’ like those you talk about since I stopped using layer masks and started using clipping paths. Of course those don’t work when it comes to hair, but I primarily work with products (tubs, faucets, etc) so that fixed my problems.
Man I thought this was just my imagination and never really sat down to experiment before. Thank you! Now if only someone could explain why saving an Illustrator file as a native file introduces a little bit of margin when placed in ID3 while placing the same file as an EPS is the perfect size…
Artifacts, smoothing, layer masks, yeah yeah fascinating stuff.
Where can I buy that top?
Macy’s.
I don’t have any problem of that kind.
I have CS3, all the latest versions on a Macintosh. I use layer masks in Photoshop or clipping path. I found the layer mask to be the most reliable approach when dealing with transparencies, particularly when importing PSD files into Illustrator. Sometimes, in the worst case scenario, if a Service Bureau has problem with transparency, then I use Transparency Flattening in Acrobat 8 Professional, before sending the file to the Service Bureau.
If I want hard edge, I use clipping path. But a lot of my work require soft edge on photography, so I use layer masks.
For 99% of all my jobs, InDesign CS3 is my main software from which I output my PDF files. I am very happy this way.
For customers who are using low quality ink jet or sometimes when I produce a PDF for laser repro, and when I don’t want to take any chance, I use Transparency flattening in Acrobat professional. Most part of the time, when I see the low quality proof at my customers, a white box appear around the pictures where transparency is applied. Here, precisely, I don’t bother too much with that, because I know that some of my customers don’t have any postscript interpreter. So, I have always set my workflow for my final destination: the commercial printer. My customers are aware of this and don’t bother.
Finally, I always prefer working with PSD files for the sake of efficiency workflow. I use to output pretty complex jobs, and with a good printer that is aware of the good techniques to output PDF with transparency, I never had any problem at all! I never had so much pleasure doing design than now. The tools are gorgeous, excellent and very mature.
It has always been an old story trying to find a way to have no problem in every situation or to please everybody. But in the real world, it doesn’t exist. I simply the workflow by choosing capable service bureaus and printers, this is my BEST warranty. Otherwise, if I would be trying to please everybody in every situation, I would pass a considerable amount of time trying to control everything, and this has a cost in time that many customers would simply refuse to pay.
Just another thought.
About the white lines that David is talking about, I am not sure if we talk about the same problem here, but here it is :
I noticed for the white lines that may occur in previewing PDF that it was more related to the Acrobat PDF compatibility version that you choose while exporting to PDF.
I have seen these white lines while I was exporting as Acrobat compatibility version 4. Since I output my files as Acrobat version 5 compatibility and up, I have never seen these white lines again.
The white lines (that go away or stay the same) that David was referring to are stitching lines. That’s the border of where transparency is flattened.
You’ll never see that on an exported PDF with PDF 1.4 or later compatibility.
I recently upgraded our Macs from InDesign CS2 to CS3 and we immediately began seeing similar lines, but unlike this issue, these lines were actually printing (as well as displaying in Acrobat). More specifically, the lines were gray, and appeared at the edges of the transparency in the PSD images (usually where a transparent background would meet up with white pixels). InDesign CS3 was putting the lines into the image data of the PDF when exporting.
After several hours of troubleshooting, I narrowed it down to certain types of downsampling (in the PDF Export Options). If I used Do-Not-Downsample or Subsampling-to… problem solved (no lines printing). They still show in Acrobat of course (as Bob points out in this article), but they don’t print as they did with Bicubic Downsampling.
I didn’t have this issue in version CS or CS2. Most of these documents were previously successful print jobs in CS2, but failed in CS3 due to this problem. I think this is somewhat rare as well, but if anyone runs into the lines actually printing, try changing the PDF Export Downsampling settings, it definitely resolved it for me.
Great article!
Great post Rik!
This is exactly the problem I’ve been having and hadn’t come up with a solution to it. It occurred as you say when white pixels met a transparent background.
I thought I was the only person who was getting this…
I’m having the artifacts problem with a psd file so I made the image a tif as you suggested. But now the tif won’t import with a transparent background - it has a white background when imported, which I cannot get rid of. I’m using CS3, the tif has a transparent background in Photoshop with the image on a layer (the only layer in the file). In Indesign the picture frame has a none background. What is going wrong?
When you save as TIF in Photoshop look at the TIF options dialog box carefully.
There’s an option to save transparency that must be checked.
Thanks Bob, that fixed it. Though I do wonder why Adobe has chosen to do it that way - if a seasoned guy like me can’t get it…..
When I tried to locate the problem I thought it had to do with jpg (which is someties the case, and using zip rather than jpg can be a way to solve stitching problems if you have access to the original InDesign document).
But if the mask and the masked images are not treated in exactly the same way there will be edge artifacts. A bit surprising that the edge pixels are black though, but then again null RGB is black.
Very helpful! I’m having problems with the color being different when it prints though. For example, where the transparent object is it’s darker. is that just me?
–I’m sorry, that wasn’t very clear, I was running out of time to edit.
I mean if I have transparent images on top of a solid color, it will appear blended and fine in ID and acrobat, but it will print with a distinct box around the image where the image is. I didn’t think this would happen if I used the Place tool.
@Jacki: I wonder if this is a problem with your printer or print driver. Does it happen this way on all printers? Also, check out the Yucky Discolored Box syndrome on the Popular FAQ posts page.
Interestingarticle. I’ve noticed the white lines and always told the customer not to worry!
Never knew why it happened or why it would not be problem.
Bob, I went into a TIF file to check “Save transparency”. It’s greyed out. What’s different here?
If there’s no transparency in the file you that choice will be grayed out.
Are .png files the PSD files referred to here?
If not, how about using .png files?
@deborah: No, PSD files are native Photoshop files. Using png files isn’t a good choice for high-resolution printing. Plus, InDesign doesn’t really handle their transparency properly, I think.
As David says, PNGs are really not the best choice for print. While they do support transparency, they don’t support CMYK and you can’t embed a color profile in them.
Another issue you might watch out for is not screen artifacts but what really can happen if you are not careful. If you are creating PDFs for print and using transparency, most of the options for creating that PDF may render a solid black box that will print instead of the nice shadow effect, for example, you desired. Ideally you would use an exported PDF with PDF 1.4 or later compatibility. Too often the shortcuts to create PDFs such as through CS3 or QuarkXPress create new problems. You have a lot more control using Adobe Distiller than a shortcut “Save As PDF” or “Export as PDF” gives you.
David, the only time you might see this is if your PDF is dropped into an application such as earlier versions of QuarkXPress that have no support for transparency or opened in a very old version of Acrobat or Reader
Because of this, you should always check with the printer or in the case of ad submissions the publication.
That said under normal circumstances, I firmly disagree with you. Exporting from InDesign yields far better and more reliable results than using distiller which will flatten any transparency.
With modern RIPs and now the Adobe PDF Print Engine, leaving transparency live is a far better workflow.
As far as having more options with distiller, sorry, but I can’t think of any with the possible exception of printing to PDF to create a grayscale PDF.
I do however agree with you as far as QuarkXPress is concerned. While I know very few people still using it, I’ve found the PDFs that it produces to be very inconsistent in quality. That of course, could be attributed to user error.