*** From the Archives ***
This article is from January 5, 2008, and is no longer current.
My $100 EPS Challenge
I just finished listening to episode 68 of InDesign Secrets podcast and the comments on the usefulness of EPS files bothered me.
So, here’s my challenge:
I will give $100 to the charity of your choice if anyone can give me a legitimate reason to save bitmapped images as EPS files.
Here are the details:
The file is created in Adobe Photoshop for placement in a page layout program.
Page layout software includes InDesign 2 or later or QuarkXPress 4 or later.
The page layout file is to be output by a modern imagesetter RIP or direct-to-plate output. This does not include ancient RIPS or specialty RIPS such as sign plotters.
Legitimate reasons include any feature in an EPS that cannot be equaled using any of the following: Photoshop, TIFF, or PDF.
For the first person to respond with a legitimate reason, I will give $100 to your favorite charity in your name. Responses will be posted here on InDesign Secrets.
I retain the option to answer any comment with an explanation of how that feature can be equaled using the three file types mentioned above.
If no one does come up with a reason by Feb. 1, I will give $100 to my local Breast Cancer support group in my name.
OK?
Let ‘er roll!
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Wow! Great challenge. Of course, the problem is what does “legitimate” mean. ;) As a co-host, I need to be clear that Sandee’s offer is made by her personally. But what a great offer!
Here are two random proposals: First, EPS can handle halftone screening commands, such as angle, linescreen, and spot type. However, these are often stripped out in modern RIPs. That said, they can be very helpful when making spot color DCS files.
Second, you could (well, I could) write a custom EPS file with postscript code that generates clever patterns of bitmapped images. Good idea? Well, it’s probably better to just use a photoshop plug-in for cool bitmapped patterns, but I bring it up because it’s important to remember that the big difference between EPS and other formats (including PDF) is that EPS is actually a little computer program that can have loops, functions, etc.
Wait a minute, David, give someone else a chance to win the $100! (I would add that “employees and contributors to InDesignSecrets.com are not eligible for Sandee’s contest!) ;-)
Thanks David for reminding me about the screening commands.
Your comment would certainly qualify you as the winner, but as Anne-Marie said, “employees and contributors to InDesignSecrets.com are not eligible.”
Lets see what the ordinary readers come up with.
Well, you can include Vector data. It will keep type, vector graphics and shapes inside the file for output.
Also it can anti-alias the appearance of a low resolution image when it’s printed.
I think I misread the question. One reason is that it has Transparent whites in Bitmap for an EPS.
Transparent whites is a legitimate reason. I tend to think this one is a winner.
However, I will wait for others to post their comments.
>Well, you can include Vector data. It will keep type, vector graphics and shapes inside the file for output.
This is an important point that most people don’t realize. Vector data can be kept inside a Photoshop PDF. In addition, while the EPS can maintain vector shapes, it does not allow you to open the file and keep the vector data. This makes the EPS less effective than a Photoshop EPS.
>Also it can anti-alias the appearance of a low resolution image when it?s printed.
I’m not clear as to what the above means. Can you clarify it Eugene?
#
Eugene
Urgh ok, I’ll try, I’m not the best at describing things. But I’ll give it a go.
Basically if you have a low resolution image and you choose, Image Interpolation from the Save EPS menu then on output the image is interpolated, which you know what that means, it tries to straighten out the jaggies by inserting pixels around the image that closely match it’s near(est) pixel(s).
If that makes sense, I’m really poor at verbalising it, I have it in my head though visually.
And the thing about the Vector Data, I know it is rasterised on opening again in Photoshop. I just wasn’t sure if it was pertinent to the comment.
An interesting challenge for sure. But I’m stumped. And I’m glad! Bitmapped EPS was always a royal pain in the ol’ days, when we needed those pesky clipping paths. The ability to place PSD & PDF have mercifully replaced all my needs for EPS. So please, folks, do *not* come up with some ingenious EPS-only idea which makes it necessary to use them again!
Klaus, when I worked in Prepress, all we did was output to EPS from Quark for our RIP. Before that everything was printed to PS and then RIPed. It was only in 2004 that we got PREPs, but even as it took in RIPed PDFs, which were PS we couldn’t escape the EPS or PS format.
I wonder how many people send PDFs to printers and they are eventually RIPed and processed as EPS or PS?
Well, if we have a duotone image and some clipping paths in Photoshop, the PSD and PDF formats will hold this in addition to EPS, though in InDesign only will work the PSD format, IIRC.
But in QXP we may have to climb up to the last version to be able to take advantage of it. Thus I think (as I’m an InDesign-only early adopter) only the old EPS would work in that scenario.
I have used DCS (form of EPS) to save multichannel files to print in earlier versions of Quark that didn’t work with PDF files. This was the only way to include the spot separated files in Quark. You did say the rules were for InDesign2 or Quark 4 or later.
I created an International Swim Competition program in the 2 colors of the sponsor which were orange and blue. I created separations for orange and blue (without a 3rd party tool) by manipulating the cyan, magenta and yellow channels in Photoshop and proofed to spot color Matchprints. The resulting program was assumed to be 4 color by everyone that picked it up including some experienced colleagues in the printing industry–but it was indeed 2-color. All flesh tones looked normal and the lane lines and the water looked normal. Orange and Blue combined at equal amounts to create grays and blacks. Even the US Flag looked good, albeit a bit orange on the stripes — most assumed it was the lighting.
Anyway– this is definitely the classiest and most clever use of EPS that I have come across. I was however, glad to see the need for EPS decrease with later software. It was kind of a resource hog in prepress.
I used to do spot color separations in the analog days with a process camera. It is rather tricky to deal with RGB filters to get something other than CMYK separations (cross masking involved with film). I never tried the software that supposedly can do this now. Has anyone used software that does this? (Pantone used to have something for this, and then later offered Hexachrome seps).
If there is no software for 2-color separations, I could be persuaded to write an article on how to do it if there is interest. Be forewarned–it has its pluses and minuses and is now harder to proof with very few printers offering spot color Matchprints these days. Even soft proofing is tricky– Photoshop’s visual presentation of spot colors is not adequate–it requires creating color layers in a separate file that is only for the purpose of soft proofing.
Jak, I too have also once acceptably simulated four-color with blue and orange spot colors — though I did it as vector AI. Ah yes, DCS is also EPS — five separate files to schlepp around, what a blessing we don’t have to deal with that anymore!
I have to design in two color for a newsletter and don’t know of any way except EPS to use duotones. If there is a more efficient way I would love to hear it.
Dawn, dutone without EPS is easy. Start with a CMYK file, then add a Spot Color Channel, then fill the CMY channels with white, then put whatever image data you need into the Spot channel (like a copy of one of the old CMY channels), then save as plain PSD. When you take this CMYK+spot PSD into ID (or perhaps even lowly Quark?) your duotone will be there, ready for separation — just run off the Black and the Spot while ignoring the CMY plates.
Addendum: the standard dutotone/tritone/quadtone creation route in Photoshop is deeply problematic: you have NO access to editing the Spot channel(s) with curves, sharpening, etc. My CMYK+spot route gives you full editing access to the Spot color(s) channels.
Final addendum (maybe!): the reason we must fill the CMY channels with white, instead of deleting them, is that deleting them will turn the CMYK file into a multichannel file — which, when saved as a PSD, InDesign refuses to import, as it will only import PSDs in RGB, LAB or CMYK (and grayscale and indexed and one-bit). But there is almost no file size penalty for keeping these extra CMY channels: the compression in PSD files deals efficiently with the three white channels, so the file bloat for the unwanted CMY channels is very modest.
Surely you could just create a mixed ink group of two spot colours in indd; then apply these new colours to grayscale images in indesign to create custom duotones?
Don’t forget to set screen angles with any of these methods. Prepress should do this at your printing vendor. They can use 45 deg. for the dominant and either the mag. or cyan angle for the secondary or lighter color. Their workflow and screening algorithms will determine particular angles and rulings.
Before we had a PDF workflow in the late 90’s, I sometimes actually pasted the spot channels in to the black and cyan or magenta channels of a blank cmyk file. Why?
Because most imagesetters and platesetters have optimized proprietary screen angles and ruling combinations. Eg. Linotype Hell/Heidelberg/Scitex/Kodak etc. image or plate setters had/have several proprietary screening strategies –if you selected 175 lines per inch, you actually get slightly different lpi in each plate and angles slightly different than 30, 75, 105, 45.
To take advantage of that optimization I often pasted the spot channels into a cmyk channel: eg. dominant color into black and secondary or lighter color into cyan or magenta, saved as regular cmyk (blank channels are white) and then gave instructions to prepress (me) to mark plates appropriately. Downside is weird previews on page-so I preferred DCS method then, now PSD.
btw–I believe Tim Gill, co-founder of Quark and original chief software mechanic, developed the DCS standard back in the day (1989-91?).
Back to InDesign–don’t forget about screen angles at output. A gentle and courteous reminder to your vendor that you have multiple spot colors involving screening is worthwhile.
There are many device control operators and graphic state operators available to the PostScript Programing language, which EPS is a part of. Many engineering test files – which often include 1 bit TIFF files at high resolutions like 48,000 ppi, – well, many test simply would not be possible without certain PostScript operators. The finest example is Dr. Henry Freedman’s resometer file – https://www.printtools.org/techwatch/resometer.php – which absolutely is (and must be) and EPS file – This tool will report the true resolution of a given marking engine (or Raster Image Processor). In a nutshell, there are many things you can do with a bitmap while it is encapsulated with specific code/operators/calls – that you can’t accomplish within the PDF specification (or even printing from Acrobat) – nor are these things available within the native Photoshop file format and certainly not available within TIFF or even ISO 12639 (TIFF/IT). Hope this helps, and who ever wins – please donate the 100 to my favorite charity, the Sandee Cohen Mensa group, as she, and she alone – is worthy. The mere fact that you proposed this challenge shows just how selfless you are, as you fearlessly admitted in public that no one can know everything and at the same time demand proof! Great stuff, now back to my own challange, adding Spectrophotometric data to image areas (or better said – areas in an image) for accurate swatch matching. 100 bucks to the first developer to mash-up L a*b* values with spectral data into XMP – and within 8 bit masks – process it in-RIP.
Jak, thanks for the screen angle reminder, a good and necessary tip! Yes, true, a 175 lpi screen is never exactly that, it might be 174,67 lpi for magenta, 176,87 lpi for black, etc. This is due to some very tricky mathematical-physical facts involved in creating angled halftone dots with the imagesetter’s high-res laser spot, which must always moves in an X & Y grid co-ordinate system. I read up on it eaons ago, it’s scary stuff — which we designers don’t need to know about — but we should know the general ballpark values of the screen angles of our spot colors. And we need to gently inform the prepress guys to mind this, also.
Not only can you use custom screen angles in your eps (and define the shape of your dots), but you can also apply custom transfer functions which allow you to change ink percentages (and boost or reduce certain colors).
Maybe with EPS DCS, you are sure that your image won’t be re-separated again regardless color management is on or off.
Transparent whites and spot colors don’t win this contest, because you can use layers in a .psd file to achieve transparent whites and retain spot colors.
Clipping paths don’t win because you can use a layered .psd file with transparent background to do the same thing.
The ONLY thing that really wins is the ability to use DCS for OPI output, in my opinion.
But Jim, a .psd will always output rasterised, as with a EPS you can choose to include the vector data. Although it won’t reopen in Photoshop (or you favourite application) as a vector as it is rasterised at that point.
Hey, while this Post is here I might try and get some info. I have received some files from an outsourced designer. The files are in Quark 7 or something. I had a friend of mine save them down to 5, as that’s all I have.
There are some EPS files, and they are not showing their previews. I have to make a PDF to see the whole shabang. I have opened the EPS images and they are saved as 1 bit TIFFs Previews.
My question is, I know that changing the bit for Previews isn’t much, but will it affect it? And as they came from a MAC and I’m working Windows, will I have to change the Encoding to ASCII from Binary? And do I need to add any of the other flavours.
Sorry for such a basic question, but I simply cannot remember as I haven’t had to work this way in 3 years and I just don’t recall.
Thanks
I haven’t used OPI in a decade, thankfully, so I’m not sure — but can’t you also use OPI for other file formats, like TIF? If so, then OPI isn’t unique to EPS.
Eugene, I think you have to
“save as” over the old files and change the preview to Tiff. And while you are at it, I do suggest you change the encoding to Binary. That may actually be necessary as well.
Thanks jimno, for some reason I thought that on Windows you would use ASCII and on Mac you’d use Binary. I’m not sure where I read that or if I’m getting my wires crossed or something. Ah I’m sure it will be ok, I’ll leave it the way it was supplied and cope without image previews.
Wow…!
A few days holliday, checking back here… and this happened!
Eh… now who won the $100 again?
In my early days on desktop publishing, i began using illustrator and photoshop as a team. I learn that the EPS combines Vector information and Raster information. This is the reason why is a more complete format for hight resolution ouput. It have the ability of produce more detailed images. Photoshop generate a kind of EPS call EPS DCS (Desktop Color Separation) which was designed to work whit Quark.
Sandee, you really know how to rile up a bunch of people! ;)
Yes, I did not expect that I would be elegible to “win.” The “win” here is that we’re all learning!
Sandee and Eugene, “Transparent whites in bitmap images” doesn’t win the contest — not because PSD can have transparent layers, but because white pixels inside TIFF and PSD Bitmap images (images that are in Bitmap mode) are already treated as transparency in InDesign. You don’t need EPS for that.
As for “Image Interpolation,” I would argue that this isn’t really relevant, either. First, it only works on some Adobe PostScript 3 printers. Second, as far as I know, it only works with low-res (like 72 dpi) images. The only workflow I can imagine using this for is including low-res screen captures or Web graphics inside an InDesign document that will be run through Distiller.
What’s wonderful about all this is that no one is actually going to profit personally.
I have extended an invitation to a friend at Adobe to review all the comments.
But if I don’t get a response, I will post my decision before the end of the week when I fly to Macworld.
Well. I cannot wait to read a full full answer on this topic.
David, how are white pixels from .psd or .tiff treated in Quark?
I used to convert things to EPS as a matter of course both as a safe multi-compatible format for vectored files, and for bitmapped files with clipping paths present. I’d use Tiffs with LZW for bitmaps with no clip path.
That was consistently most reliable back in the Quark days and I continued to do the same once I’d switched to inDesign…
however, I have the lovely combination of CS2 and Intel macs to thank for my almost total abandonment of EPS. It seems that even the most simple EPS placed in inDesign CS2 will cause it to crash when you try to RIP or create a PDF using an Intel Mac. Adobe’s solution to this is to tell you to upgrade to CS3, but unfortunately I don’t have that sort of cash kicking around. This was beginning to rankle slightly and so I gave up, and now just drop .ai and .psd files straight in. No problems.
I used to avoid this for the sake of some poor soul who may come along and want to edit any of my artwork with Freehand / Quark XPress …but sod it. They can embrace the 21st century and learn to use inDesign instead.
Yesterday I got a phone call from a colleague who wanted to view an Aldus/Adobe Persuasion file he created 8 years ago. Ooops…. Maybe we need to stick to open file formats like EPS so that artwork can still be used in 8 years time when PSD is only remembered as a relic from the glorious Adobe past?
I think EPS is the only way if you want to import an image created in PS in multichannel mode to Indesign. Multichannel mode is use in Silkscreen printing.
We use bitmapped EPS files whenever possible in our magazine layouts because they bloat the Indesign document file size the least (we will use PSD files 1 or 8 bit transparency affects). I have done many experiments over the years with Indesign and Quark and have found that because the layout programs do not generate JPG previews for EPS files, EPS filled layouts will be as much 40% smaller in file size than an equivilant layout containing any combination of PSD, TIF, PDF or JPG files.
The smallest achievable layout file size is critical to pushing Indesign and Incopy documents over a thin WAN between two remote locations from a central K4 publishing server.
(To be clear I am talking about Indesign and Incopy file size shrinking, not the file size of the placed images).
To conduct your own experiments make you use the same images with the same DPI, (a 72 dpi image will create a gigantic preview versus a 300 dpi image at the same pixel dimensions), color space, etc. an be sure to do a Save as of each layout before you compare the file sizes.
It would be great if someone could prove me wrong, as still using EPSs in 2008 is a burden (converting the files, integration with digital asset management systems, etc.)
So what’s the answer to this question?
My answer to the challenge:
I consulted with David Blatner and Steve Werner the other day. (All three of us standing in the middle of the Macworld show floor discussing this issue.)
The answer that was most compelling to me, screen angles, is really moot since modern RIPs will most always strip out the screen angle info.
So, the final answer is….(drum roll please):
I won the challenge!
I will be sending $100 to my favorite breast cancer support organization in New York City.
Well, congratulations on declaring yourself the winner of your own contest. This sort of thing might raise an eyebrow at an ANSI or ISO meeting, but hey, since you are good at deciding things, my request is that the three of you quickly get back together and declare who wins the OpenDocument Format (ODF) and Ecma 376 Office Open XML (OOXML) contest so we can be done with that. Oh, and and thanks for helping Warner Home Video / Blu-ray thing.
Just so you REALLY REALLY know, you were right – and Dov says so ! Read all about that on my silly little blog –
https://michaelejahn.blogspot.com/
oh – just a little semantics issue – most consumer RIPs don’t ‘strip out’ screening info, they ignore them, and it has nothing to do with modern – more modern or better said -‘advanced’ RIPS – offer ways to replace, override, honor or ignore screening and many other PostScript attributes.
Thanks for the bandwidth!
oops – may have spoke too soon.
Stephan Jaeggi, a PDF Guru in Switzerland just wrote me;
The only way I can get a CMYK image with the correct ICC profile in a
device independent PDF document from a QuarkXPress 7 page is importing an
EPS file (with enabled PostScript color management), then exporting an PS
file and using Distiller to create the PDF. (Doesn’t work with the
built-in PDF Creator; here you only get a PostScript CIEBasedDEFG CSA
Profile without a useful name).
39. Kyle: I can appreciate the desire to make your files smaller. However, I just tested bringing two 4 mb images into a new INDD document and saving them… 5 file formats: PSD, PDF, TIFF, JPG, and EPS. You’re right that EPS was smaller, but only 9K smaller than PDF and maybe 50K smaller than PSD or TIFF. I was pretty careful (each INDD document was new; not saved over the last).
This is easy: screen shots. If you are reproducing a screen shot (or any bitmap, actually) and you want it to reproduce perfectly, pixel by pixel, without antialiasing, Photoshop EPS is the way to go. I’ve done tons of manuals where I’ve had to resize screen shots and nothing else ever quite looked right.
Joecab, that is curious. I’ve been printing screen shots since 1990 and have never found EPS to be of better quality. I usually use TIFF. If you’re getting antialising when printing, something else is going wrong.
Really? Hm I’m going to have to experiment a little to see what’s really going on. Or it could be a very old habit from the early 1990’s that I never let go of.
because I feel like it
What about duotones?
CJ, as was mentioned earlier, duotones are usually best saved as PSD files.
Well, i need to make an duotone indesign book, 1 specific red en 1 specific blue, but i also need to export it to pdf for preview and the document refuses to export the cmyk+2 spotchannels .psd, but it will export the multichannel .eps. Now, after reading Klaus Norby’s method, I just spent alot of time making the cmyk+2 .psd s, now i can’t get em into a regular color space anymore…
There seems to be some communication gap regarding the term “bitmapped image” as it it used in the challenge description. Photoshop calls any 1-bit (black & white) image “bitmap” for color mode; Windows has a Bitmap file format with the extension BMP; Any pixel-based image can be described as bitmapped (sometimes called raster).
I hardly ever use the Photoshop EPS format. I will generally save a color photo or line art as a TIFF with LZW compression. Our imagesetter has problems with JPEG-encoded EPS files, and high-res images can be huge if not compressed some way.
The benefit to EPS images is that they always print every pixel. TIFF images often get subsampled when printed from Quark, PageMaker, InDesign, etc. Quark has an option called “Full Resolution TIFFs” to handle that issue. InDesign and PageMaker have similar options.
Printing a screen shot without turning on the Full-res-TIFF option will surely yield unsatisfactory results. Quark on a Mac also has a bug (feature?) where the PDF Export uses the Full-Res-TIFF option only if you have it selected in the print window.
MathType.
Even the Mac 6.0 beta. : /
Just catching up on the outcome of this great contest.
Jak, I would be interested in learning more about your work flow for this process.