Epson Color Stylus Calibration for Adobe Photoshop 3.0
January, 1995
by Nathaniel Merriam (72202,142)
The included files were used to calibrate my monitor and my Epson color stylus printer. I hope the several hours I spent on this task can be saved by others, either by using my settings (which might very well work for many people), or using my methodology and the included helpful files.
The files that are included:
Epson.api -- this is my Photoshop file for printing ink setup. It was made with 3.0, but I think it's usable by 2.5 as well. You can use it by selecting File-> Preferences-> Printing Inks Setup, and then selecting "load" from the dialog. I doubt Macintosh users will be able to use this file directly, but Photoshop is amazing cross-platform, so I won't swear to it. If you're on a Mac and need the settings, enter them manually according to the table below.
x | y | Y
------------------------------- C | .173 | .215 | 20
| | | M | .5 | .255 | 15
| | | Y | .44 | .52 | 64
| | | MY | .61 | .32 | 14
| | | CY | .28 | .5 | 10.4
| | | CM | .2053 | .1245 | 6
Calibrat.tif -- this is an LZW compressed TIFF that I made with 2 large gray ramps and large boxes filled with pure C, Y, M, CY, CM, and MY. It also has two linear gradations from Cyan to MY, one clockwise spectrum, and the other counter-clockwise spectrum. I found this useful for judging intermediate (non-pure) color behavior.
Moncal.gif -- this file is actually from Tom Price (75300,620). It's an invaluable tool for determining your monitor's native gamma. You should have your monitor set up correctly under File-> Preferences-> Monitor Setup before you attemp calibration with the printer. I got this file from the old Aldus Forum when Photostyler still existed. I don't know if it's available anywhere else on CServe, so I included it here. One note on using the file -- don't view it from Photoshop -- use a GIF viewer that doesn't adjust the monitor, or it won't give you an accurate reading.
readme.txt -- this file. I'll put all the standard stuff here -- you can feel free to upload and distribute this file wherever you like, and you can seperate the files, too (I'm not particular). I would suggest that you keep them all together, for the ease of the uncalibrated guy who gets them, though. You may not charge for any of these files -- heck, i did all the hard work, and I'm willing to share. :)
Calibration:
First, use Moncal.gif and the monitor setup to get your monitor in tip-top shape. As PShop's help file states, tape down your contrast and brightness settings, since any changes in these throws off the whole calibration.
I printed out a copy of calibrat.tif and testpict.jpg (which comes with Pshop 3, in the calibration subdirectory) at 720 dpi on the special paper. If you're going to the trouble of calibrating the printer, then I assume you're doing your final prints at the highest possible quality. You have to print all the calibration pages at the same resolution, and on the same paper as you'll be using in the future, or your prints won't be accurate. For example, the colors are much lighter at 360 dpi than at 720, even on the special papers. If you need to, calibrate for both resolutions and save each as a seperate profile that you can load when needed.
At this point, I went into that mind-numbing screen that comes up when you select "custom" from the Printing inks setup dialog. I didn't try to do it by the numbers (mainly, because I have no idea what the numbers mean). Instead, clicking on a color square will bring up a normal color picker, which you can adjust for C, Y, M, CY, CM, and MY. The goal at this stage is to pick the color closest to the printed page, which is no small task.
Significant changes:
I noticed that the green prints much darker than the screen -- it's also pretty easy to select a green that's close to the print.
The Cyan was much darker on the print than the screen -- it was pretty difficult to find a good comprimise. I changed this several times in the course of a few hours as I saw it affecting the monitor. This is where my experience saves you time -- you don't need trial and error.
The Magenta displays as far too purple. I decreased the blue and increased the red. Another tricky match, much trial and error.
The Yellow, as is typical, is too bright on screen. I added a bit of red to move it closer to orange and decreased both saturation and lightness. This actually came to a pretty good match after fighting with it for a while.
The MY had to be moved closer to red/touch of orange and deepened a bit. A reasonable match.
CM was actually pretty good -- I think I deepened it a bit, but I imagine leaving it alone wouldn't have hurt at all.
Lingering problems:
The magenta ink is tough to match because of the "glow" it has in light. i wound up lightening the screen version to accomidate for this trait.
The Cyan ink is a little bit more to royal blue than you can get onscreen.
After all this color calibration was done, I had a little problem -- the gamma seemed wrong. The shadows weren't as deep onscreen as they were on the prints. Oops -- I realized I hadn't touched the dot gain setting yet. I found that settings around 25-35 were good, my personal setting being 29. With that done, I could honestly say I had a damn good match -- hope you do too.
if anyone has comments, questions, or settings they'd like to share that work for them, I'd be more than happy to hear from them. If somebody finds that everything works for them as I have it here, I'd also like to hear -- this was my first full-scale closed loop calibration, and I'm paranoid that I did something horribly wrong (g)...
